JPS5839458B2 - Acetylene black manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing acetylene black which has a small amount of hydrochloric acid absorption and excellent filling properties of a chain structure with a small degree of development, and more specifically, a method for producing acetylene black that has a small amount of hydrochloric acid absorption and excellent filling properties of a chain structure with a small degree of development. This invention relates to a method for producing acetylene black having a chain structure with a small amount of hydrochloric acid absorption and a small degree of development, by supplying the same to a pyrolysis furnace and thermally decomposing the same.

Conventionally, acetylene black has superior electrical conductivity compared to other carbon blacks, and has therefore been used in applications that take advantage of this property, such as mixtures for dry batteries, conductive rubbers, and resins.

However, although acetylene black has excellent physical properties such as a lower amount of impurities than other blacks, excellent electrical conductivity, and a well-developed chain structure, it has poor filling properties and compressibility, and is bulky. There are drawbacks.

The present invention solves these drawbacks by thermally decomposing acetylene and fine powder of graphite or graphitizable carbon in a mixed state to produce acetylene with a poorly developed chain structure and a small amount of hydrochloric acid absorption. The aim is to provide a black manufacturing method.

That is, the present invention uses acetylene and graphite or graphitizable carbon in an amount of 1 to 2 graphite or graphitizable carbon relative to the theoretical amount of acetylene black when the acetylene is thermally decomposed.
Supply the pyrolysis furnace in a mixed state such that the weight core is 0 weight,
This is a method for producing acetylene black characterized by thermal decomposition at 2300 to 2500°C.

The present invention will be further explained in detail below.

Conventional acetylene black is obtained by thermally decomposing acetylene, and the production method of the present invention is basically the same.

However, the difference is that acetylene and graphite or graphitizable carbon powder are supplied in a mixed state to a thermal decomposition furnace and thermally decomposed.

The graphite or graphitizable carbon used in the method of the present invention is preferably of high purity and has a fineness of 100 mesh or less.

A specific example is needle coke.

The mixing ratio of graphite or graphitizable carbon powder to acetylene varies depending on the shape of the furnace, operating conditions, yield, etc., so it is difficult to specify, but it is 1 to 20% of the theoretical amount of acetylene black when the acetylene is thermally decomposed. It is necessary to contain a weight factor.

If the content of the graphite or graphitizable carbon powder is less than 1% by weight, the amount of hydrochloric acid absorbed will not be less than 10 cc/5 g, and the acetylene black filling property will not improve.

Moreover, if it exceeds 20% by weight, the amount of hydrochloric acid absorbed decreases too much, making it impossible to achieve the object of the present invention.

To carry out the method of the present invention, graphite or graphitizable carbon powder is supplied to acetylene in a mixed state at the above ratio to a conventional acetylene decomposition furnace, and the temperature is 1800°C or higher, preferably 2300 to 2500°C. You just have to keep it in place and disassemble it.

The acetylene and graphite or graphitizable carbon powder can be mixed by suspending them in acetylene or by spraying them separately through a nozzle.

As explained above, the present invention is a method for producing acetylene black which is thermally decomposed by supplying powders such as acetylene and graphite in a mixed state to a pyrolysis furnace. , an excellent black similar to acetylene black can be obtained, which has a low hydrochloric acid absorption amount, a bulk specific gravity of 10 times or more, and a similar electrical conductivity.

Acetylene black obtained by the method of the present invention has properties similar to graphite, and since it is acetylene black, it contains few impurities.

Therefore, it can be used in applications that take advantage of its electrical conductivity and filling properties, such as as an electronic conductor for positive electrode mixtures of alkaline or alkaline manganese batteries.

The present invention will be further explained below with reference to Examples.

Example 1 5% by weight of scaly graphite powder of 100 meshes or less based on 50 m'/h of acetylene with a purity of 99.9 volume and the theoretical amount of acetylene black produced by thermal decomposition of the acetylene.
A vertical pyrolysis furnace (with an inner diameter of 500 mm
im) and thermally decomposed at a temperature of 2300°C to obtain acetylene black.

The measured values of the physical properties are shown in the table.

The amount of hydrochloric acid absorbed is significantly reduced, the bulk specific gravity is about 10 times that of the conventional acetylene black, and the electrical resistivity is also improved compared to the conventional product.

Example 2 10% by weight of acicular coke powder of 100 mesh or less
The same procedure as in Example 1 was conducted except that the temperature was 2500°C.

[Brief explanation of drawings]

The drawing is an electron micrograph of the novel acetylene black of the present invention.

Claims (1)

[Claims] 1 Acetylene and graphite or graphitizable carbon are mixed in a pyrolysis furnace in such a manner that graphite or graphitizable carbon has a weight ratio of 1 to 20 cores relative to the theoretical amount of acetylene black when the acetylene is thermally decomposed. 2300-25
A method for producing acetylene black characterized by thermal decomposition at 00°C.