JPS6112888A - Manufacture of electrode binder - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for producing electrode binders from coal tar products.

BACKGROUND OF THE INVENTION In order to produce carbon shaped bodies, such as carbon and graphite electrodes, from specialty coke, cokingable binders are required. Coal tar binders are preferably used for this purpose.

Demand for electrode binders has recently increased. Initially, emphasis was placed on particularly high coking residues, but later on the quality of the binder was also emphasized, which is the difference between toluene insoluble (T1) and quinoline soluble (Ql), the high coking residue of β-resin. The proportion was noticed.

The meaning of quinoline solution (Ql) has been determined differently in the past. This should be viewed in the context of the respective technology of electrode and anode fabrication. .

It is previously known that the coking residue of hard pitch can be increased by thermal after-treatment following distillation (
West German Patent No. 670187). Since an increase in the coking residue also increases the insolubles (Ql, TI), it was proposed to reconstitute the hard pitch distilled under vacuum with high-boiling tar oil (see German Patent No. 1,182,247). .

Since the importance of beta resins with respect to binding capacity became known, binders with high beta resin content, but low Ql content, have been desired. German Patent Application No. 1 282 655 describes a continuous process for the preparation of an electrode binder, which process consists of heat-treating coal tar standard pitch in multiple steps at elevated temperatures, the resulting pitch distillation being The material is fed to the respective preliminary processing steps.

The development of coking processes combined with careful raw material selection now provides high purity coke with high electrical conductivity for electrode production.

The graphite structure is already well pre-formed in the coke.

However, this coke has a drawback of low strength. To ensure that the electrode does not lose its strength, it is necessary to embed the coke in a strong binder coke framework.

DE 1929508 A1 describes a method for producing refractory materials with high compressive strength. As a binder, a mixture of coal tar pitch and heat treatment residues from the pyrolysis of mineral oil fractions has been proposed. The binders are also said to be suitable for producing electrode materials. However, increasing compressive strength has only been confirmed for dolomite-based refractory materials. Furthermore, it is known that mineral oil binders are unsuitable for electrode production compared to coal tar binders.

It is common to all known thermal processes that the content of quinoline solution increases at the same time as the β-resin content in the binder increases. For this reason, it has also been proposed to add high-boiling oils to the pitch before treatment, which partially thermally polymerize to form beta resins. However, this newly formed quinoline solution (Ql) is different from the one that existed from the beginning.

Problem to be Solved by the Invention It is therefore an object of the present invention to be able to produce a binder with a sufficient Q1 component with a high C/H ratio as well as a high coking residue and a sufficient β-resin component. The present invention provides a method for producing electrode binders from coal tar products.

Means for Solving the Problems The above-mentioned problems can be solved by the present invention.
Distillate from pyrolysis of coal tar pitch at temperatures higher than 800 °C and coal tar standard pitch with softening point according to Sarnau (:IEP(-8)) 3 = 1 to 1:
3 in liquid form and the mixture is distilled under normal pressure or vacuum to a Kremer-Sarnau softening point of 90 to 130°C and the distillation residue optionally has an average boiling point higher than 350°C. The solution is to mix it with a coal tar fraction having a

The distillate from the pyrolysis of coal tar pitch is preferably that produced during coking of hard pitch at approximately 1000° C. in a horizontal chamber furnace.

EFFECTS OF THE INVENTION Surprisingly, the mixture used in the present invention, unlike other mixtures of coal tar pitch and high boiling coal tar distillate, can be easily distilled in a retort under normal pressure or vacuum. It has been found that significantly higher yields of binder with a high co-1 content can be obtained by using the quinoline solution, and the C/H ratio of the quinoline solution is likewise higher than that of the other mixtures.

EXAMPLES The method of the invention will now be illustrated by way of non-limiting examples.

Example 1 The following characteristic data: E P (K − S ) 72.5°C T I
24.1% by weight Q l
From a horizontal chamber furnace characterized by 50 parts by weight of coal tar standard pitch with 6.2% by weight and T I 8.6% by weight 91 70% by weight Onset of boiling 272°C Boiling residue at 360°C 93% by weight of pitch coke oven was mixed at 150°C in a retort and 12
Distill at a power of 0 mbar to a softening point of 995°C (-8). At this time, the maximum temperature of the can part is 360°C.

In this case, with a yield of 68% the following analytical data: Density at 20 °C 1.32.7 cm3TI
32.5% by weight Ql
12.1% by weight coking residue (Conradson)
A hard pitch with a C/H4,06 of 592% by weight Q1 is obtained.

This microphotograph shows no anisotropic structure. This pitch can be used directly as an electrode binder.

Example 2 Characteristic data: EP (K-5) 71.5℃TI,
19.6% by weight Q l
50 parts by weight of coal tar standard pitch having 7.3% by weight, and ■1
70% by weight Ql 6.3
Melt and mix together 50 parts by weight of pitch coke oil characterized by wt% boiling onset 262°C and residual content at 350°C 91% by weight. The mixture is distilled at normal pressure, with a maximum bottom temperature of .

The temperature is 490°C. With a yield of 68.3%, the following analytical data: T I 36.9% by weight Q
I 15.6 wt% coking residue (Conradson) 627 wt% Q1 C/f
A hard pitch is obtained with a softening point (K-5) of 116°C, with -13.90°C. 100 parts by weight of the hard pitch thus obtained and high boiling point coal tar oil (start of boiling 183°C, 35%
By mixing 5 parts by weight (residual content at 0°C: 62.5% by weight), the following analytical data: E P (K - S ) 99.5°C T
I 35.7% by weight Q1
"149 weight weight - oxidation residue (Conradson) 58.4 weight t% Q1 C/H3,6
A suitable electrode binder having a ratio of 9 is obtained.

Example 3 (comparison) Example 2 is repeated under the same conditions, except that instead of pitch coke oil, high-boiling coal tar distillate (start of boiling 240°C; residual at 350°C 85°C) is used. use.

With a yield of 53.0%, the following analytical data: T I 38.1% by weight Q
I 12. ．． 5 wt% coking residue (Conradson) 618 wt% Q1 C/H
It has 3,37. A hard pitch is obtained with a softening point of 114.5°C.

With approximately the same softening point and coking residue, this pitch has a lower Q1 than the hard pitch produced according to the present invention.
content and low C/H ratio. In microphotography,
Menphases with diameters greater than 60 μm are identified. Furthermore, the yield is clearly low.

Claims (1)

[Claims] 1. A method for producing an electrode binder from a coal tar product, in which a coal tar standard pitch having a Kremer-Sarnau softening point of 60 to 80°C is mixed with coal at a temperature higher than 800°C. Distillate from pyrolysis of tar pitch and 3
:1 to 1:3 and the mixture is distilled under normal pressure or vacuum to a Kremer-Sarnau softening point of 90 to 130°C and the distillation residue optionally
A method for producing an electrode binder, characterized in that it is mixed with a coal tar fraction having an average boiling point higher than °C. 2. As a distillate from the pyrolysis of coal tar pitch, about 1
2. The method of claim 1, wherein pitch coke oil produced at 0.000°C is used. 3. A method according to claim 1 or 2, wherein the coal tar standard pitch and the distillate from the pyrolysis of coal tar pitch are mixed in a 1:1 ratio. 4. The method according to any one of claims 1 to 3, wherein the distillation is helmet distillation.