JPS6141942B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for adjusting the ratio of DBP value of granular carbon black/DBP value after compression. Carbon black is manufactured by known manufacturing methods such as flame carbon black method, channel carbon black method, gas carbon black method, furnace carbon black method or oven carbon black method, and the quality of carbon black is determined by the particle size of the initial particles. In addition to surface area, surface characteristics due to carbon black structure [oxygen-containing group],
Due to unsaturated groups, extractable content (Extraktgehalt)]
Usually determined. Carbon black structure is understood to be the carbon black appearance that occurs when the initial particles are formed in an erect manner or are connected in a more or less grape cluster or peristaltic animal shape. and,
The reason why the initial particles are connected in this way is that they form either a rigid bond (as in the production of carbon black) or a loose aggregate. In the case of carbon black manufacturing methods such as the channel carbon black method or the gas carbon black method, the structure of the formed carbon black is as follows:
It is defined by the method used and is not affected by any modifiability of the operations in that method. On the other hand, in the case of the production of furnace carbon black, it is possible to change the starting materials introduced during the production of carbon black (see German Patent No. 1592864 and German Patent No. 1592863) or by adding additives. (German patent
1220540), there is a possibility that the structure of carbon black is affected. And because of this possibility, it is known that the furnace carbon black process makes it possible to produce a wide variety of different types of carbon black, each exhibiting a limited range of structures.
At the same time, the quality of the carbon black can be adapted to various requirements in various fields of production of rubber mixtures, printing inks, synthetic resins, etc. In order to adjust the carbon black quality to a constant level, it is first necessary to control the carbon black obtained by various manufacturing methods. The structure formation by linking the initial particles of carbon black is confirmed optically using an electron microscope. However, performing and evaluating electron micrographs is extremely time consuming and expensive, so this method is not preferred for controlling and managing carbon borage production. Conventionally, simple methods for determining the carbon black structure have been known, and one of them, for example, is the oil absorption quantitative method. According to this oil absorption determination method, oil is mixed dropwise into carbon black and thoroughly ground with a spatula until the paste reaches a certain consistency. The carbon black may also be shaken and mixed with oil in an Erlenmeyer flask until only one sphere is formed. However, these methods often depend on the skill level of the practitioner and are not sufficiently accurate. A relatively accurate method that is very widely used today to determine the structure of carbon black is the dibutyl phrethalate absorption value measurement method according to ASTM-D2417-75. The key point is to drop diptylphthalate from a brewer onto a certain amount of carbon black until a sudden increase in force occurs in the kneader. This test result (hereinafter referred to as DBP value) is 40 to 200 ml DBP/100 g carbon black in the case of ordinary commercially available carbon black. The DBP value is the primary specification among carbon black consumers and manufacturers, because it is a measure of the processability and dispersibility of carbon black. However, recently, normal DBP values (normale
DBP-Zahl) is a non-collapsible structure (nicht
It has been pointed out that it contains a part of the primary structure, that is, a part of the collapsible structure, that is, a part of the secondary structure. Primary structure is a good measure for predicting rubber industry data. The DBP value after compression will be explained in detail as a test method. The method for measuring the DBP value after compression is as follows. 25 g of carbon black is placed in a steel cylinder with a diameter of 32 mm and a pressure of 13.5 tons (1700 Kg/cm ² ) is applied using a push rod. After about 5 seconds, the sample is removed from the compression device and minced in a magnetic mortar. The compaction operation including fragmentation is repeated three more times, and finally the material processed in this way is
DBP value was measured according to ASTM-D2417-75. The DBP value after compression was 35 to 130 ml DBP/100 g carbon black in the case of ordinary commercially available carbon black, which was lower than the regular DBP value. In the rubber processing industry, the DBP value of granulated carbon black for rubber and the DBP value after compressing it are specified. The reason is that the two values are considered to be completely different technical measures. Although it is clear that carbon blacks with high DBP values and carbon blacks with high DBP values after compression exist, carbon blacks with various DBP value/DBP value after compression ratios are usually required. has been done. The object of the present invention is to produce granulated carbon black.
The purpose is to find a way to adjust the ratio of DBP value/DBP value after compression. In order to keep the ratio of DBP value/DBP value after compression to a low value, the present invention sets the rotation of the shaft of at least one granulator to be high and/or the main part of the water is
While adding water from the upstream water spray part of the flow,
In addition, in order to keep the ratio of DBP value/DBP value after compression at a high value, the rotation speed of the shaft of the above-mentioned granulator should be set low and/or the main part of the water should be diverted to the downstream side of one flow. Granular carbon black is produced by continuously mixing carbon black with water using a wet granulator while adding water from a spray section, granulating the carbon black, and then drying the wet granular carbon black.
It is in the method of adjusting the ratio of DBP value/DBP value after compression. The method of the invention can be carried out regardless of the type of granulator used. Granulators can have any diameter and are distinguished by the configuration of the needles. Although the method of the present invention can be carried out regardless of the number of passages in the granulator, it is preferable to use a granulator having 1 to 4 passages. The rectangular tank (passage) for passing granules may be arranged either horizontally or vertically. The position of the water spray section can be changed by switching the water spray device or by using two water spray sections in principle and supplying them with varying amounts of water. The method of the invention is carried out by observing three things. 1 Adjustment of the rotation speed of the shaft of the wet granulator 2 Position of the water spray section 3 Distribution of water amount in the water spray section To increase the ratio of DBP value/DBP value after compression, adjust the rotation speed of the granulator It is best to keep it low and add water by means of a spray device located downstream (back half) of the stream. If two water spray sections are used, the main part of the water is sprayed from the downstream position (back half) of the flow. Here, keeping the rotational speed of the granulator low means that the rotational speed is lower than 400 rpm. If it is necessary to lower the DBP value/DBP value after compression, it is best to increase the rotation speed of the granulator and add water using a spray device located upstream (front half) of the flow. When using two water spray sections, it is necessary to spray the main part of the water from the upstream position (front half) of the flow. Increasing the rotational speed of the granulator here means that the rotational speed is higher than 400 rpm. The amount of water added per hour is determined in each case so that an optimum granulation is produced. The optimum amount of water addition has been achieved when the granulated carbon black leaving the granulator contains unwetted powdered carbon black (dry processing) and sticky aggregates (wet processing). By varying the water feed rate at two very distant water feed points present in the granulator,
This makes it possible to carry out the method of the invention particularly favorably, resulting in particularly high-quality granules. Another advantage of the present invention is that the feed rate at the upstream or downstream water feed location can be easily varied without changing the transmission and the water nozzle, thereby increasing the DBP value/DBP after compression. It becomes possible to easily adjust the ratio of values over a wide range. Furthermore, it is possible to use not only two supply sections, but also more than two supply sections, or even nozzle groups, provided that this conforms to the technical idea of the invention. The method of the present invention will be explained in detail below using examples.
The method of the present invention is not limited to these examples. Example 1 For testing, carbon black manufactured by the furnace carbon black method and having the following physical and chemical measurements was used. Iodine adsorption according to DIN53582 93mg/g Initial particle diameter determined by electron microscopy
25mm PH value 9 Carbon black is 113~ in granulated form
Must have a DBP value of 116ml/100g. A fine correction of the DBP value of the powdered carbon black introduced into the granulation process was performed by adding additives to the reactor. The carbon black thus obtained was wet-granulated in a known structure in a granulator. FIG. 1 shows a schematic diagram of a known granulator. According to FIG. 1, carbon black is fed by a feed pipe 1 into a passage 2 of the granulator. Passage 2
The shaft 3 of is driven by a motor 4. On the shaft 3, short needles are arranged in a spiral manner in the carbon black introduction region 5 and longer needles in the intermediate region 6. After passing through the passage 5, the carbon black falls from the connecting pipe 7 into the passage 8. The passage 8 basically has the same structure as the passage 2. That is, in the passage 8, a shaft 9 is driven by a motor 10, and on the shaft 9, a short needle is arranged in a region 11 and a longer needle is arranged in a region 12. The inner diameter of the two passages (rectangular vessels for passing particulate matter) is 512 mm. The prepared granular carbon black was placed in tube 1.
3' is discharged from the granulator. The granulator used has four water spray sections along its entire length.
It comprises W ₁ , W ₂ , W ₃ and W ₄ and can be used individually or together during operation. 420 kg/h of powdered carbon black with a DBP value of 122 ml/100 g was continuously introduced into the granulator, the rotational speed in passage 2 was 640 rev/min and that in passage 8 was 300 rev/min. Adjusted. Water was introduced from the water spray section _W1 at a rate of 420/h. After exiting the granulator, the carbon black was dried in a drying trommel at a temperature of 160°C. Regarding dried granular carbon black,
The DBP value and the DBP value after compression were determined. DBP value 114ml/100g DBP value after compression 100ml/100g DBP value/DBP value after compression 1.140 DBP value - DBP value after compression 14ml/100g Example 2 The granulator of Example 1 was used. The rotational speed of passage 2 was adjusted to 350 revolutions/min and that of passage 8 to 300 revolutions/min. 420 kg/h of powdered carbon black with a DBP value of 121 ml/100 g was added.
Water was added at a rate of 455/h from water spray section _W1 .
After drying the moist granules in a drying tromel at 160° C., the DBP value and the DBP value after compression were measured on the dry granular carbon black. DBP value 113ml/100g DBP value after compression 98ml/100g DBP value/DBP value after compression 1.153 DBP value - DBP value after compression 15ml/100g Example 3 The granulator of Example 1 was used. The rotational speed of passage 2 was adjusted to 350 rpm and that of passage 3 to 300 rpm. To this, 245/h from water spray part W ₂
, and 245/h of water was introduced from the water spray section _W3 . After drying the obtained granular carbon black at 160°C in a drying tromel, the DBP value and the DBP value after compression were measured. DBP value 114ml/100g DBP value after compression 97ml/100g DBP value/DBP value after compression 1.175 DBP value - DBP value after compression 17ml/100g Example 4 The granulator of Example 1 was used. aisle 2, aisle 8
The rotation speeds were adjusted to 350 rpm and 300 rpm, respectively. Addition of water is carried out at the water spray part W ₂ ,
It was carried out by W ₃ in a ratio of 38:62. 118ml/
Powdered carbon black 420 with DBP value of 100g
Kg/h was introduced continuously. Addition of water is 200/h in water spray section W ₂ , and 200/h in water spray section W _3.
The speed was 3300/h. After drying the granular carbon black at 160°C in a drying tromel, the DBP value and the DBP value after compression were determined. DBP value 116ml/100g DBP value after compression 96ml/100g DBP value/DBP value after compression 1.208 DBP value - DBP value after compression 20ml/100g Table 1 summarizes the results obtained in the above examples.
It will be like this. 【table】

[Brief explanation of the drawing]

The drawing shows an example of a device for carrying out the method of the invention. 1: supply pipe, 2: passage, 3: shaft, 4: motor, 5: carbon black introduction area of passage 2,
6: intermediate region of passage 2, 7: connecting pipe, 8: passage,
9: shaft, 10: motor, 11: front region of passage 8, 12: middle region of passage 8, 13: discharge pipe,
W ₁ , W ₂ , W ₃ , W ₄ : Water supply section.

Claims (1)

[Claims] 1. In order to keep the ratio of DBP value/DBP value after compression to a low value, the rotational speed of the shaft of at least one granulator should be set high and/or the main part of the water should be directed upstream of one stream. While adding water from the water spray part,
In order to keep the ratio of DBP value/DBP value after compression at a high value, the rotation speed of the shaft of the above-mentioned granulator should be set low and/or the main part of the water should be transferred to the downstream water spray of one stream. DBP of granular carbon black, characterized in that carbon black is continuously mixed with water using a wet granulator, granulated, and then the wet granular carbon black is dried.
How to adjust the ratio of value/DBP value after compression.