JPH0625313B2 - Manufacturing method of coal-based filler - Google Patents

Description

Detailed Description of the Invention Technical Field: The present invention relates to a novel method for producing a coal-based filler, and more particularly to a method for economically advantageously producing a coal-based filler that has excellent rubber reinforcing properties and plastic reinforcing properties and is suitable for use in the rubber industry, tire industry, plastics industry, etc.

BACKGROUND ART Carbon black, a type of rubber reinforcing agent, has been widely used in various fields, for example, as a reinforcing agent for tires and rubber, a black pigment for printing inks and paints, a resin colorant, a material for dry batteries, and a conductive material. In particular, the demand for carbon black as a reinforcing agent for tires and rubber accounts for an overwhelming majority, and carbon blacks of various qualities are used for this reinforcing agent.

Carbon black has been produced up until now by incomplete combustion or thermal decomposition of petroleum-based or coal-based hydrocarbon gases or hydrocarbon oils, such as natural gas, petroleum gas, crude naphthalene, creosote oil, and pitch oil, as raw materials, and known production methods include the furnace method, channel method, and thermal method.

However, these methods using hydrocarbon gases or hydrocarbon oils as raw materials have drawbacks such as unstable raw material conditions and unavoidable high costs due to the complicated manufacturing process.

On the other hand, in order to overcome these drawbacks, a method has been proposed in which, when producing carbon black using coal as a starting material, solid coal is directly pyrolyzed to produce coal-based carbon black for use as a rubber reinforcing agent, without using fractions such as creosote oil or crude naphthalene obtained by dry distillation of the coal (Japanese Patent Publication No. 16107/1963). However, the carbon black of the coal-based filler obtained by this method contains a large amount of ash, which reduces the tensile stress of the rubber and retards the vulcanization of the rubber, making it unsuitable for use as a rubber reinforcing agent.

In view of the above circumstances, an object of the present invention is to provide an economical method for producing a coal-based filler, which is excellent in rubber reinforcement properties, using solid coal as a raw material.

DISCLOSURE OF THE INVENTION As a result of extensive research into achieving the above-mentioned object, the present inventors have found that the above-mentioned object can be easily achieved by using a novel method in which an ultrafine ground slurry obtained by subjecting coal to a specific treatment is subjected to a specific deashing and granulation treatment, i.e., a deashing and granulation treatment by a specific oil agglomeration method suitable for granulating ultrafine particles, thereby completing the present invention.

That is, the method for producing the coal-based filler of the present invention is as follows:
It consists of steps (a) to (d).

(a) A pyrolysis process comprising pyrolyzing coal having an ash content of 10% by weight or less and pulverized to a particle size of 10 mm or less at 500 to 2000°C, followed by cooling.

(b) Add a dispersion medium to the obtained pyrolyzed product to obtain a concentration of 10 to 100%.
A micronizing step which comprises preparing a 50% by weight slurry and micronizing it until the average particle size of the slurry particles is 5 μm or less.

(c) Adding water to the obtained ultrafinely pulverized slurry,
The slurry concentration is adjusted to 1 to 20% by weight, and a boiling point of 1
Oil at 50°C or less is added in an amount of 30 to 100 parts by weight of dry solids.
A granulation step comprising adding 300 parts by weight of oil and stirring to granulate the carbonaceous material with the oil, and separating and recovering the granulated material from the water.

(d) A drying step in which the obtained granules are heated at 50 to 300°C to evaporate the water and oil, followed by drying and cooling.

The present invention will be described in detail below.

The coal to be pyrolyzed in step (a) has an ash content of 10% by weight.
Preferably, the ash content is 7% by weight or less, and more preferably 3% by weight or less. Examples of coal used as a raw material include anthracite, bituminous coal, subbituminous coal, lignite, lignite, and peat. Among these, coal with an ash content of 10% by weight or less, or coal that can be selected to have an ash content of 10% by weight or less by gravity separation or the like, is desirable. Furthermore, non-caking or weakly caking coal is advantageous from the viewpoint of ease of pulverization after pyrolysis, and non-caking coal is particularly advantageous. These coals may be used alone or in combination of two or more types.

In the method of the present invention, in order to reduce the ash content in the product, coal with a low ash content is selected from the coals,
It is desirable to use this as the raw material, or, if necessary, select coal with a low ash content by gravity separation or the like and use this as the raw material.

To separate coal with an ash content of 10% by weight or less from coal with a high ash content, for example, flotation or heavy liquid separation may be used to separate the coal by specific gravity, and coal with a low ash content and low specific gravity (specific gravity of about 1.3 or less) may be selected.

In the method of the present invention, the coal is subjected to pyrolysis by carbonization,
The volatile components are decomposed and removed by pyrolysis, and pulverized coal is used for uniform processing during pyrolysis. The preferred particle size of the pulverized material depends on factors such as the type of pyrolysis furnace, the heating temperature, and the amount of volatile components and ash in the coal, and cannot be generally limited. However, generally, any particle size that allows for rapid and uniform removal of volatile components during pyrolysis is sufficient, and coarsely pulverized coal to a particle size of 10 mm or less is used. Any conventionally used method can be used as the pulverization method.

This crushing treatment may be carried out prior to the gravity separation.

The pyrolysis treatment is carried out by subjecting the pulverized coal to a pyrolysis treatment at 500 to 2000°C, preferably 550 to 1000°C, under an air-shielded condition.
The pyrolysis is typically carried out by heating for 2 to 3 hours at a temperature in the range of 1800°C, more preferably 600 to 1500°C. This pyrolysis may be carried out under vacuum or in an atmosphere of an inert gas such as nitrogen or an inert industrial waste gas. However, a preferred method is to carry out the pyrolysis in a gas mixture of hydrogen, methane, carbon monoxide, carbon dioxide, and the like generated by pyrolysis of coal while shielded from air. The pyrolysis furnace may be either continuous or batch-type, as long as it is sealed. Conventional heating methods, such as electric heating and gas heating, can be used. However, in the process of the present invention, gas combustion heating is preferred because combustible gases, such as methane and other hydrocarbon gases, hydrogen, and carbon monoxide, generated from the volatile components generated by pyrolysis can be recovered and used as a heating source.

If the pyrolysis temperature is less than 500°C, volatile matter remains, and even if the resulting coal-based filler is compounded into rubber as a rubber reinforcement agent, the rubber reinforcement effect is low. In addition, the vulcanization reaction of the rubber is inhibited during vulcanization, and volatile matter is released.
On the other hand, if the temperature exceeds 2000°C, graphitization will proceed and it will not be possible to obtain a coal-based filler with the desired rubber reinforcing properties.

The solid matter of the coal after the pyrolysis (hereinafter referred to as char) is usually cooled in the absence of air.

Next, in step (b), the solid matter (char) of coal obtained by pyrolysis is treated to form particles with an average particle size of 5
The particles are ultrafinely pulverized to a size of 1 μm or less, preferably 1 μm or less.

If the average particle size is larger than 5 μm, the rubber reinforcement properties (tensile properties, abrasion resistance, flex resistance, heat resistance, etc.) will be reduced.

The ultrafine grinding machine to be used may be a ball mill or the like.

This ultrafine pulverization is carried out by dispersing the char in a dispersion medium to form a slurry. Here, in order to increase the pulverization efficiency, the char may be coarsely pulverized in advance as necessary,
It is desirable to use a particle size of about 200 mesh or less. As the dispersion medium, various substances other than water can be used. The slurry concentration is 10
In order to improve the grinding efficiency, it is desirable to increase the slurry concentration to about 30 to 50% by weight by adding an appropriate dispersant to the slurry. Furthermore, the grinding efficiency can be further improved by adding or using an appropriate antifoaming agent in combination to suppress the generation of bubbles in the slurry.

As the dispersant and antifoaming agent, those commonly used in carbon-water slurries can be used.

Examples of such dispersants include polystyrene sulfonic acid, polycarboxylic acid, lignin sulfonic acid, etc. Examples of antifoaming agents include methanol, ethanol, acetone, etc.

The ultrafinely pulverized char slurry can be obtained by the above method. If necessary, the ultrafinely pulverized char slurry can be subjected to separation and classification to remove foreign matter and coarse particles that may reduce the reinforcing properties of the rubber.

That is, the coarse particles contained in the ultrafinely pulverized product or its slurry are classified and removed together with foreign matter. The particle size of the coarse particles to be removed is usually 5 μm or more, preferably 2 μm.
The above is the minimum requirement. If coarse particles with a particle size larger than 5 μm remain, the rubber reinforcement properties of the resulting coal-based filler are reduced. Iron contained in the raw coal or mixed in due to wear of the equipment, grinding media, etc. can be effectively removed by using a magnet. If iron remains, it may contaminate the surfaces of rolls and molds when the resulting coal-based filler is kneaded and compounded into rubber.

As the separation and classification method, a conventional method such as a centrifugal separation method or a wet cyclone method can be used.

In order to improve the separation efficiency during this wet separation and classification, it is desirable to disperse or dilute the ultrafinely ground product or its slurry in a dispersion medium or diluent such as water to adjust the slurry concentration to usually 1 to 20% by weight, preferably 5 to 10% by weight.

Furthermore, by adding an appropriate dispersant to the slurry system, particularly a dispersant for uniformly dispersing particles with strong cohesive forces in the slurry, the separation and classification efficiency can be further improved. As such a dispersant, the above-mentioned dispersants can be used.

Next, in step (c), the ultrafinely pulverized slurry that has been separated and classified is subjected to deashing and granulation. Since ash reduces the rubber reinforcement properties, the ash contained in the ultrafinely pulverized material is separated and removed, and the ultrafinely pulverized material is granulated to make it suitable for handling as a product and for blending with rubber.
The granules should be of a suitable strength so that they can be easily and uniformly dispersed in the rubber during kneading.

One of the particularly important points of the method of the present invention is that the oil agglomeration method using a low boiling point oil is employed as a method for simultaneously carrying out deashing and granulation.

This demineralization and granulation by oil agglomeration method is
Taking advantage of the fact that ash is hydrophilic while carbonaceous matter is lipophilic, this method involves adding low-boiling oil to a water slurry of ultrafinely pulverized material, stirring it, agglomerating only the carbonaceous matter with the oil, and then granulating it to separate it from the ash. The agglomerated and granulated carbonaceous matter is separated and recovered from the slurry using a sieve or net, and sent to the next drying process. By adopting this method, the water and oil contained in the granules are evaporated and removed, and the strength of the granules is provided solely by the cohesive force of the ultrafinely pulverized particles, making it possible to achieve a granule-like structure without using a binder.
Granules free from binder oil and the like can be obtained.

In conventional coal oil agglomeration methods, heavy oils or the like are used to increase the strength of the granules, and these oils remain in the granules, which reduces the reinforcing properties of rubber when used as a reinforcing agent for rubber, etc. However, the oil agglomeration method of the present invention does not have such problems.

The slurry concentration of the ultrafinely pulverized material-water slurry used in the oil agglomeration method of the present invention may be 1 to 20% by weight, preferably 5 to 10% by weight.

The temperature at which this oil agglomeration is carried out is usually 0 to 60°C, but it is preferably carried out at room temperature.

The treatment time is usually about 1 to 30 minutes, preferably 5 to 15 minutes.
A minute or so is sufficient.

The oil added for deashing and granulation by oil agglomeration can be any of paraffinic, aromatic, and naphthenic oils having 8 or less carbon atoms, but an oil having a boiling point of 150°C or less is used, which can be easily evaporated and removed in the subsequent drying process. Preferably, an oil having a boiling point of 120°C or less, for example,
Low molecular weight hydrocarbon oils such as aromatic oils such as toluene, benzene, and xylene, and aliphatic oils such as hexane, heptane, and octane, and fluorocarbons such as trichlorotrifluoroethane are used.

These may be pure or in mixtures,
It may also contain water, and may also contain a process oil for rubber in part.

The oil is added to the ultrafinely pulverized material-water slurry in an amount of 30 to 300 parts by weight per 100 parts by weight of the ultrafinely pulverized material as a dry solid.

If this value is less than 30 parts by weight, aggregation and granulation do not occur, and the ash cannot be removed in parts, whereas if it exceeds 300 parts by weight, the granulated particle size becomes too large.

A particularly preferred range of this addition ratio depends on the type of oil used,
It varies depending on the slurry concentration and is not uniformly specified,
The amount is preferably 75 to 150 parts by weight.

By the above-mentioned method, the ash content in the carbonaceous material separated and recovered by deashing and granulation is reduced to 5% by weight or less, preferably 2% by weight or less.

If the amount of ash is more than 5% by weight, when the resulting coal-based filler (product) is used as a reinforcing agent for rubber, the durability of the rubber will be reduced by increasing internal heat generation, increasing wear, increasing flex cracking, and increasing compression set, and the mechanical properties such as tensile strength and elongation will also be reduced.

Thus, ash significantly deteriorates the dynamic and static properties, and also significantly lengthens the vulcanization time, which is an important factor in the productivity of vulcanized rubber, thereby reducing workability.

The particle size of the demineralized and granulated product can be easily adjusted by the amount of oil added, but from the standpoint of ease of handling the product, it is desirable to set this secondary particle size (granulated product particle size) to about 0.5 to 3 mm.

Granulation of ultra-finely ground material by oil agglomeration is
Ultra-finely pulverized materials, which tend to scatter and are difficult to handle, can be granulated in a slurry state, so the working environment is not adversely affected.

In this way, the ultrafinely pulverized material is deashed and granulated by oil agglomeration, and then dried to produce a product. The particle strength of the product is sufficient for practical use even when low-boiling oil is used, but if the strength can be further increased, a binder substance can be dissolved in the oil to carry out oil agglomeration, and the product can then be produced by drying to evaporate only the oil.

As the binder, a typical rubber compounding agent that does not adversely affect the rubber reinforcement, such as a higher fatty acid such as stearic acid or palmitic acid, is preferably used.

Furthermore, in order to improve the compatibility of the obtained coal-based filler with rubber and further increase the rubber reinforcing properties, oil agglomeration can be carried out using oil in which a surface modifier for ultrafinely pulverized particles has been dissolved, and the oil can be evaporated by drying to uniformly coat the surface of the deashed and granulated coal-based filler with the modifier.

Effective surface modifiers include process oil, which is a type of rubber compounding agent, activators, vulcanization accelerators, etc. Conventionally, surface modifiers have been added during rubber compounding, but adding them during filler production can shorten the complexity of the rubber compounding process.

Next, in step (d), the carbonaceous granules recovered by the deashing and granulation, i.e., the undried coal-based filler, are dried and cooled to remove the moisture contained therein and to evaporate and remove the low-boiling oil and the like used in the oil agglomeration, thereby obtaining the target coal-based filler, which is then used as a product.

This drying can be carried out by various ordinary drying methods, for example, under an inert gas atmosphere such as nitrogen gas,
The reaction is carried out at 50 to 300°C, preferably 100 to 200°C, and more preferably 110 to 150°C.

The drying and cooling can be carried out either continuously or batchwise. The dryer and cooler can be any of the commonly used dryers and coolers.
To prevent the granulated particles from being broken down and powdered, a rotary kiln or fluidized bed type dryer or cooler is preferred.

In the present invention, the ultrafine pulverized material is dried after granulation by the oil agglomeration method and the water is separated. Therefore, compared with the case where the ultrafine pulverized material slurry is directly dried,
The amount of heat required for drying can be significantly reduced.

That is, the undried coal-based filler recovered after granulation by the oil agglomeration method contains 0.3 to 1 kg of water and 0.3 to 2 kg of the solvent used in the oil agglomeration method per 1 kg of dried ultrafinely pulverized material, but the amount of heat (energy) required to dry this is only 1/3 to 1/30 of that required when directly drying the slurry, which allows for a significant reduction in the amount of heat (energy) required for drying and allows drying to be carried out significantly faster.

The table below shows an example of a comparison of the amount of heat required for drying.

The oil evaporated in the drying device can be cooled and condensed, and the water can be separated, recovered, and recycled.

The coal-based filler produced in this way has extremely excellent and well-balanced rubber reinforcing properties and is inexpensive, so it can be suitably used as a rubber reinforcing agent in fields such as the rubber industry and tire industry. That is, by kneading and compounding the coal-based filler produced by the method of the present invention into rubber, it is possible to significantly improve various thermal and mechanical properties of the rubber, such as heat resistance, flex resistance, abrasion resistance, tensile strength, tear strength, and elongation, and to achieve excellent effects such as shortening the vulcanization time.

BEST MODE FOR CARRYING OUT THE INVENTION Comparative Example 1 Celejon coal (subbituminous coal) was used as a raw material and was thermally decomposed in a batch-type box furnace at a temperature of 750°C for 3 hours. After that, the coal was cooled to room temperature, and water was added to form a slurry with a solids concentration of 30% by weight. The slurry was then wet-pulverized to submicron particle sizes in a media-agitation ball mill.

Water was added to this ultrafinely pulverized slurry to dilute it to a solids concentration of 10% by weight, and after removing the iron contained in the slurry with a magnet, the coarse particles were separated using a wet cyclone.

The ultrafine powder slurry from which the coarse particles have been separated and removed is heated at 120°C.
The sample was dried at room temperature for 24 hours to evaporate the water, and then subjected to a rubber compounding test.

Comparative Example 2: Celejon coal (subbituminous coal) was used as the raw material and was subjected to gravity separation using a liquid with a specific gravity of 1.40. Coals with a specific gravity of 1.40 or less were selected and then thermally decomposed in a batch-type box furnace at a temperature of 750°C for 3 hours. After that, the coals were cooled to room temperature and water was added to form a slurry with a solids concentration of 30% by weight. The slurry was then wet-pulverized to submicron particle sizes using a media-agitation ball mill.

Water was added to this ultrafinely pulverized slurry to dilute it to a solids concentration of 10% by weight, and after removing the iron contained in the slurry with a magnet, the coarse particles were separated using a wet cyclone.

The ultrafine powder slurry from which the coarse particles have been separated and removed is heated at 120°C.
The sample was dried at room temperature for 24 hours to evaporate the water, and then subjected to a rubber compounding test.

Comparative Example 3 The same procedure as in Comparative Example 2 was carried out except that coal having a specific gravity of 1.30 or less, which had been subjected to gravity separation using a liquid having a specific gravity of 1.30, was used.

Example 1: Cerrejon coal (sub-bituminous coal) was used as a raw material, and was subjected to gravity separation using a liquid with a specific gravity of 1.30 to select coal with a specific gravity of 1.30 or less.
The material was coarsely crushed to a particle size of 10 mm or less, and then subjected to thermal decomposition in a batch-type box furnace at 750°C for 3 hours. After that, the material was cooled to room temperature, and water was added to form a slurry with a solids concentration of 30% by weight. The slurry was then subjected to wet ultrafine crushing to submicron particle sizes in a media-agitated ball mill.

Water was added to this ultrafinely pulverized slurry to dilute it to a solids concentration of 10% by weight, and after removing the iron contained in the slurry with a magnet, the coarse particles were separated using a wet cyclone.

Toluene (boiling point 110.7°C) was added to the ultrafine powder slurry from which the coarse particles had been separated and removed at a ratio of approximately 1 m per 1 g of solids, and the mixture was stirred. Secondary particles granulated to a particle size of approximately 1 mm by oil agglomeration were collected on a sieve, and the ash was separated and removed.

The granulated particles thus recovered were dried at 120° C. for 24 hours to evaporate the water and toluene, and then subjected to a rubber compounding test.

Example 2 The same procedure as in Example 1 was carried out except that Celejon coal was used without being subjected to gravity separation.

Example 3 The same procedure as in Example 1 was carried out except that coal having a specific gravity of 1.26 or less, which had been subjected to gravity separation using a liquid having a specific gravity of 1.26, was used.

Example 4 The same procedure as in Example 1 was carried out except that coal having a specific gravity of 1.35 or less, which had been subjected to gravity separation using a liquid having a specific gravity of 1.35, was used.

Comparative Example 4 Loy Yang coal (brown coal) was used as the raw material and was thermally decomposed in a batch type box furnace at a temperature of 650°C for 2 hours, then cooled to room temperature, and water was added to form a slurry with a solid concentration of 30% by weight, which was then wet-pulverized to submicron particle sizes in a media-agitation type ball mill.

Water was added to this ultrafinely pulverized slurry to dilute it to a solids concentration of 10% by weight, and after removing the iron contained in the slurry with a magnet, the coarse particles were separated using a wet cyclone.

The ultrafine powder slurry from which the coarse particles have been separated and removed is heated at 120°C.
The sample was dried at room temperature for 24 hours to evaporate the water, and then subjected to a rubber compounding test.

Example 5 Loy Yang coal (brown coal) was used as the raw material. This was coarsely crushed to a particle size of 10 mm or less and thermally decomposed in a batch-type box furnace at a temperature of 650°C for 2 hours. After that, the mixture was cooled to room temperature, and water was added to form a slurry with a solids concentration of 30% by weight. This was then wet-pulverized to submicron particle sizes in a media-agitated ball mill.

Water was added to this ultrafinely pulverized slurry to dilute it to a solids concentration of 10% by weight, and after removing the iron contained in the slurry with a magnet, the coarse particles were separated using a wet cyclone.

To the ultrafine powder slurry from which the coarse particles have been separated and removed, toluene is added at a ratio of about 1 ml per 1 g of solids, and the mixture is stirred.
2. Granulated to a particle size of approximately 1 mm by oil agglomeration
The ash was separated and removed by collecting the secondary particles through a sieve.

The granulated particles thus recovered were dried at 120° C. for 24 hours to evaporate the water and toluene, and then subjected to a rubber compounding test.

Comparative Example 5 GPF carbon black (Nitelon #55, manufactured by Nippon Steel Chemical Co., Ltd.) produced by the Oil Fornes process was subjected to a rubber compounding test.

Comparative Example 6 The same procedure as in Comparative Example 1 was carried out except that Celejon coal was used as the raw material and water was added to form a slurry without thermal decomposition.

Comparative Example 7 The same procedure as in Example 5 was carried out except that the thermal decomposition of Loy Yang coal was carried out at 400°C.

Example 6 The same procedure as in Example 5 was carried out except that the thermal decomposition of Loy Yang coal was carried out at 500°C.

Example 7 The same procedure as in Example 5 was carried out except that the thermal decomposition of Loy Yang coal was carried out at 650°C for 3 hours.

Example 8 The same procedure as in Example 5 was carried out except that the thermal decomposition of Loy Yang coal was carried out at 900°C for 3 hours.

Example 9 The same procedure as in Example 5 was carried out except that the thermal decomposition of Loy Yang coal was carried out at 1100°C for 3 hours.

Example 10 The same procedure as in Example 5 was carried out except that the thermal decomposition of Loy Yang coal was carried out at 1500°C for 3 hours.

Comparative Example 8 The same procedure as in Example 5 was carried out except that the thermal decomposition of Loy Yang coal was carried out at 1800°C for 4 hours.

Example 11 Loy Yang coal (brown coal) was used as the raw material. This was coarsely crushed to a particle size of 10 mm or less and thermally decomposed in a batch-type box furnace at a temperature of 650°C for 3 hours. After that, the mixture was cooled to room temperature, and water was added to form a slurry with a solids concentration of 30% by weight. This was then wet-pulverized to submicron particle sizes in a media-agitated ball mill.

Water was added to this ultrafinely pulverized slurry to dilute it to a solids concentration of 10% by weight, and after removing the iron contained in the slurry with a magnet, the coarse particles were separated using a wet cyclone.

To the ultrafine powder slurry from which the coarse particles had been separated and removed, trichlorotrifluoroethane (boiling point 47.6°C) was added at a ratio of approximately 1 m per 1 g of solids and stirred. Secondary particles granulated to a particle size of approximately 1 mm by oil agglomeration were collected on a sieve to separate and remove the ash.

The granulated particles thus recovered were dried at 120° C. for 24 hours to evaporate the water and trichlorotrifluoroethane, and then subjected to a rubber compounding test.

Example 12: Polystyrene sulfonic acid 0.0% was added to the slurry before ultrafine grinding.
The same procedure as in Example 7 was carried out except that 2% by weight of the powder and 5% by weight of ethanol were added and ultrafine grinding was carried out.

Example 13: 0.02 mg of stearic acid, a rubber compounding agent, was dissolved in 1 ml of toluene, and the resulting mixture was mixed with 1 ml of toluene to obtain a slurry containing 100% toluene.
The procedure was the same as in Example 7, except that oil agglomeration was carried out by adding 1 ml of cellulose acetate to 1 g of cellulose acetate.

Example 14: A rubber process oil (Diaana Process Oil AH manufactured by Idemitsu Kosan Co., Ltd.) was mixed with 0.95 m of toluene.
-5 8) The same procedure as in Example 7 was carried out except that a solution of 0.05m was added at a ratio of 1m per 1g of solids in the slurry to carry out oil agglomeration.

The properties of the raw coal and the products of Comparative Examples 1 to 4 and Examples 1 to 5 are shown in Table 1, and the properties of the raw coal and the products of Comparative Examples 5 to 8 and Examples 6 to 14 are shown in Table 2.

In order to accurately determine the effect of ash content in the measurements of moisture, ash and volatile content of the products in Tables 1 and 2, samples dried at 105°C or higher were used, and therefore the moisture content is 0%.

The primary particle size was measured by a high-speed centrifugal sedimentation method using an automatic particle size distribution measuring device (CAPA-500) manufactured by Horiba, Ltd.

Next, the coal-based filler thus obtained was used in the following formulation, and the mixture was kneaded using an 8-inch twin roll in accordance with JIS K 6383 synthetic rubber SBR testing method.
Mooney viscosity was measured in accordance with the physical testing method for unvulcanized rubber in accordance with the 6300 standard.
The vulcanization conditions were set using a mold, and the rubber compound was vulcanized.

Rubber Compound Composition (1) SBR 1500 100 parts by weight (2) Zinc Oxide No. 1 5 parts by weight (3) Stearic Acid 1 part by weight (4) Vulcanization Accelerator DM 1.2 parts by weight (5) Vulcanization Accelerator TS 0.2 parts by weight (6) Sulfur 2 parts by weight (7) Activator (Acting B) 3 parts by weight (8) Coal-Based Filler (Variable Amount) parts by weight The amount of coal-based filler was varied as shown in Table 3.

Here, the amount of coal-based filler is the same as that of Comparative Example 1 in order to strictly compare the influence of the ash contained therein in Comparative Examples 1 to 4 and Examples 1 to 5.
The amount of carbonaceous material excluding ash was set to be the same for each comparative example and example, and the amount of coal-based filler was determined so that only the amount of ash was varied, and the effect of ash on rubber reinforcement was compared. In other comparative examples and examples, the amount of coal-based filler was set to 50 parts by weight.

The components compounded into the rubber were manufactured by the following manufacturers.

(1) Styrene butadiene rubber manufactured by Japan Synthetic Rubber Co., Ltd. (2) Sakai Chemical Industry Co., Ltd. (3) Asahi Denka Co., Ltd. (4) Dibenzothiazole disulfide manufactured by Ouchi Shinko Chemical Co., Ltd. (5) Tetramethylthiuram monosulfide manufactured by Ouchi Shinko Chemical Co., Ltd. (6) Powdered sulfur #325 manufactured by Hosoi Chemical Co., Ltd. (7) Yoshitomi Pharmaceutical Co., Ltd. The physical properties and other characteristics of the rubbers kneaded with the coal-based fillers obtained in Comparative Examples 1 to 8 and Examples 1 to 14 and vulcanized are shown in Tables 4 and 5.

1) Based on JIS K 6300 2) 155°C, JSR curatometer Tmax standard (commercially available black T90) 3) Based on JIS K 6301, tensile speed 500 mm/
min, measurement temperature 25°C, test piece No. 3 dumbbell 4) Compliant with JIS K 6301, tensile speed 500 mm/
min, measurement temperature 25°C, test piece type B 5) Conforms to JIS K 6301, JIS A hardness tester 6) Goodrich flexometer, measurement temperature 50°C,
Amplitude 0.225 inch, load 241b, rotation speed 180
0 rpm, measurement time 25 min 7) Based on JIS K 6301, measurement temperature 23 ° C, 2
mm notch 8) Conforms to JIS K 6301 9) Conforms to JIS K 6301, measurement temperature 70°C, measurement time 22 hours 10) BS Standard 903 Part A9 C Method *, **, *** are based on Comparative Example 1 and Comparative Example 3, respectively.

Among the rubber reinforcing properties of carbon black, abrasion resistance, heat resistance and flex resistance are particularly important.

In carbon black, these properties vary depending on the grade (particle size and strength of structure).
Generally, materials with excellent abrasion resistance have poor heat resistance, and conversely, materials with excellent heat resistance have poor abrasion resistance.

The smaller the values of internal heat generation, flex cracking and Akron abrasion shown in Tables 4 and 5, the better the heat resistance, flex resistance and abrasion resistance, respectively.

In Examples 1 to 5 compared to Comparative Examples 1 to 4, the ash contained in the coal was separated and removed by gravity separation and oil agglomeration, or by oil agglomeration alone. In carbon black, abrasion resistance and heat resistance are contradictory properties, and improving one of them will result in a deterioration of the other. However, when comparing Comparative Examples 1 to 3 with the corresponding Examples 1 to 4, it is clear that in the coal-based filler, by separating and removing the ash, internal heat generation, flex cracking, and Akron abrasion are all reduced, and both the contradictory properties of heat resistance and abrasion resistance are improved, which means that ash has a negative effect on all of the properties of abrasion resistance, heat resistance, and flex resistance. Furthermore, as in Examples 1 to 4,
The coal-based filler in which the amount of ash remaining in the filler was separated and removed to about 5% by weight or less showed significant improvements in heat resistance, abrasion resistance, and flex resistance compared to Comparative Example 1 in which the ash was not separated and removed.

In Example 4, which corresponds to Comparative Example 5, the results were similar to those of Examples 1 to 4, which correspond to Comparative Examples 1 to 3.

Ash also has a negative effect on other rubber reinforcing properties. By separating and removing ash from coal-based fillers, the vulcanization time can be shortened, and the tensile properties, such as tensile strength, elongation, and tensile strength, are improved. In addition, the rebound resilience is improved and compression set is reduced. Thus, separating and removing ash from coal-based fillers is highly significant from the perspective of overall rubber reinforcing properties.

In addition, the carbon black of Comparative Example 7, which was produced by the oil furnace method, was compared with the carbon black of Comparative Example 7, which was produced by the pyrolysis treatment at a temperature of 500 to 1500°C.
Comparing the results of Examples 6 to 10 at 100°C, the coal-based filler has tensile strength equal to or greater than that of oil furnace carbon black, and also has desirable characteristics for rubber reinforcement performance, such as small internal heat generation and flex cracking, and high impact resilience.

Comparative Example 6, in which no pyrolysis treatment was performed, is Example 6-1.
Compared to 0, the vulcanization time is longer, 100% stress, tensile strength,
In addition, the rubber reinforcement performance is poor, with low tear strength and large flex cracks.

Similarly, Comparative Example 7, in which the pyrolysis temperature was 400°C, was
Compared to 〜10, the vulcanization time is longer, 100% stress, 30
On the other hand, in Comparative Example 8, in which the pyrolysis temperature was increased to 1800°C, the 100% stress, tensile strength, and tear strength were low, and the flex cracking was large compared to Examples 6 to 10.
300% stress, tensile strength decreases, and internal heat generation increases.

Similarly, good results were obtained in Example 11, in which oil agglomeration was carried out using Freons.

In addition, in Example 12, in which a dispersant and an antifoaming agent were added to the slurry before ultrafine pulverization and then pulverization was carried out, the particle size of the obtained coal-based filler was small and pulverizability was improved.

Examples 13 and 14, in which a higher fatty acid was used as a binder to increase the strength of the coal-based filler granules by the oil agglomeration method, had higher tensile strength than Example 7, which was not surface-treated.

As described above, the coal-based filler of the present invention, which is produced directly from coal, has excellent static and dynamic properties compared to carbon black produced by the oil furnace method.

<Basic formulation> (1) SBR 1500 100 parts by weight (2) Zinc oxide No. 1 5 parts by weight (3) Stearic acid 1 part by weight (4) Vulcanization accelerator DM 1.2 parts by weight (5) Vulcanization accelerator TS 0.2 parts by weight (6) Sulfur 2 parts by weight (7) Activator (Acting B) 3 parts by weight (8) Coal-based filler (Variable amount) parts by weight Note 1) The amount of carbon blended in Comparative Examples 1 to 4 and Examples 1 to 5 was varied based on Comparative Example 1 so that the amount of carbonaceous material in each example was the same. In the other Comparative Examples and Examples, 50 parts by weight was blended.

Note 2) Acting B was only blended with coal-based filler.

INDUSTRIAL APPLICABILITY The present invention provides a novel method for inexpensively and efficiently producing a coal-based filler from coal that has high rubber reinforcing properties and well-balanced rubber reinforcing properties.

Claims (4)

[Claims] [Claim 1] A method for producing a coal-based filler, comprising the following steps (a) to (d): (a) a pyrolysis step in which coal pulverized to a particle size of 10 mm or less and having an ash content of 10% by weight or less is pyrolyzed at 500 to 2000°C and then cooled; (b) a dispersant is added to the pyrolyzed product to obtain a pyrolyzed product with a concentration of 10 to 1000°C;
(c) preparing a 50% by weight slurry and ultrafine-pulverizing the slurry particles until the average particle size of the slurry particles is 5 μm or less;
The slurry concentration is adjusted to 1 to 20% by weight, and a boiling point of 1
Oil at 50°C or less is added in an amount of 30 to 100 parts by weight of dry solids.
(d) a drying step in which the resulting granules are heated at 50 to 300°C to evaporate the water and oil, followed by drying and cooling; [Claim 2] A method for producing a coal-based filler, comprising the following steps (a) to (d): (a) a pyrolysis step in which coal pulverized to a particle size of 10 mm or less and having an ash content of 10% by weight is pyrolyzed at 500 to 2000°C and then cooled; (b) an ultrafine grinding step in which the resulting pyrolysis product is pulverized to 200 mesh or less, a dispersion medium is added to the resulting product to prepare a slurry with a concentration of 10 to 50% by weight, and the slurry particles are ultrafinely ground until the average particle size is 5 μm or less; and (c) water is further added to the resulting ultrafinely ground slurry to form a slurry of the resulting product.
The slurry concentration is adjusted to 1 to 20% by weight, and a boiling point of 1
Oil at 50°C or less is added in an amount of 30 to 100 parts by weight of dry solids.
(d) A drying process in which the obtained granules are heated at 50 to 300°C to evaporate the water and oil, followed by drying and cooling. [Claim 3] A method for producing a coal-based filler, comprising the steps of (a) a pyrolysis step of pyrolyzing coal having an ash content of 10% by weight or less and pulverized to a particle size of 10 mm or less at a temperature of 500 to 2000°C, followed by cooling; (b) adding a dispersant to the pyrolyzed product to a concentration of 10 to 2000°C;
A 50% by weight slurry was prepared, and iron contained in the slurry was removed with a magnet.
(c) adding water to the resulting ultrafinely ground slurry to obtain a finely ground product;
The slurry concentration is adjusted to 1 to 20% by weight, and a boiling point of 1
Oil at 50°C or less is added in an amount of 30 to 100 parts by weight of dry solids.
(d) a drying step in which the resulting granules are heated at 50 to 300°C to evaporate the water and oil, followed by drying and cooling; [Claim 4] A method for producing a coal-based filler, comprising the steps of (a) a pyrolysis step of pyrolyzing coal having an ash content of 10% by weight or less and pulverized to a particle size of 10 mm or less at 500 to 2000°C, followed by cooling; (b) adding a dispersant to the pyrolyzed product to a concentration of 10 to 2000°C;
(c) A 50% by weight slurry is prepared, and the coarse particles contained in the slurry are classified and removed using a wet classifier, followed by ultrafine pulverization until the average particle size of the slurry particles is 5 μm or less.
The slurry concentration is adjusted to 1 to 20% by weight, and a boiling point of 1
Oil at 50°C or less is added in an amount of 30 to 100 parts by weight of dry solids.
(d) a drying step in which the resulting granules are heated at 50 to 300°C to evaporate the water and oil, followed by drying and cooling;