JP2010144003A - Method of manufacturing carbon black, carbon black obtained by the method, and rubber composition containing the carbon black - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide: a method of manufacturing carbon black which achieves a high value in the 24M4DBP without increasing a hydrogen content in comparison with conventional carbon black; the carbon black obtained by the manufacturing method; and a rubber composition. <P>SOLUTION: The method for manufacturing carbon black comprises introducing a raw material oil into the high temperature combustion gas flow by spraying at the upper course end in a reaction zone, forming a reacting gas flow containing the carbon black owing to the thermal decomposition reaction, then terminating the reaction by quenching the reaction gas flow by means of the introduction of a quenching medium into the reaction gas flow at a reaction termination zone, wherein this method for manufacturing carbon black having the characteristics of a low hydrogen content and a high-value 24M4DBP comprises controlling a flow rate at the position of introduction of the raw material oil, a dwell time until the temperature peak at the initial period of the thermal decomposition reaction, and a heat history at the thermal decomposition reaction. Also there are provided: the carbon black obtained by this manufacturing method; and the rubber composition obtained by blending the carbon black with a rubber. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing carbon black capable of achieving both good reinforcement and low heat buildup as a rubber composition for a tire tread when blended with a rubber component, and maintaining fatigue resistance, and carbon obtained therefrom The present invention relates to black and a rubber composition containing the same.

  Carbon black is based on the thermal cracking or incomplete combustion of the feedstock that is generated in the furnace and / or sprayed into the high-temperature combustion gas that is generated outside and introduced into the furnace. Industrially useful raw material produced in furnaces that operate under tightly controlled chemical reactions. Mechanical properties, especially tensile strength and wear resistance, for rubber compounding compositions. Since it has a unique property that characteristics such as property can be dramatically improved, it is widely used as a reinforcing filler for various rubber products including tires.

  Carbon black for rubber compounding is based on the physicochemical characteristics, ie, the diameter of the unit particles constituting the carbon black, the surface area per unit weight (specific surface area), the degree of particle connection (structure), and the surface properties. Therefore, various carbon blacks having different characteristics are selectively used depending on the required performance of the rubber product, the environment in which it is used, and the like.

  The rubber composition used for the tire contact surface (tread) is excellent in resistance to abrasion (reinforcing) because it contacts the road surface while rotating at high speed, and at the same time due to repeated deformation from the road surface to the tire. Elongation characteristics that greatly affect the fatigue resistance and cut resistance of the rubber composition are also important factors. It is known that these two characteristics are contradictory to each other, that is, if one characteristic is improved, the other characteristics are degraded, especially in large tires for trucks and buses. It has become a technical issue.

  As a carbon black that gives high abrasion resistance to a rubber composition used for a tire tread, a carbon black having a larger specific surface area or a higher structure is generally adopted, but not only control of basic characteristics, The compatibility with rubber compounding properties including wear resistance by controlling the size and distribution of aggregates, the smallest dispersion unit, void volume, crystal structure, oxygen-containing functional group content, and hydrogen content has been studied. Various solutions have been proposed.

  For example, paying attention to constituent elements other than carbon contained in carbon black and surface activity, inventions that specify the amount of hydrogen on the surface of carbon black (such as Patent Documents 1 and 2), or the sum and ratio of the amount of hydrogen and oxygen The specified invention (Patent Documents 3 and 4, etc.) or the invention (Patent Document 5 etc.) specifying the structure of carbon black, the hydrogen release rate, and the toluene coloring transmittance has been proposed.

  However, these conventional technologies can achieve both wear resistance and low heat generation to some extent mainly by controlling the degree of participation in the interaction between the carbon black surface and the polymer. Therefore, it cannot be said that it has sufficient performance with respect to resistance to fatigue deterioration due to the above, and there is a concern about deterioration in cut resistance.

Japanese Patent Application Laid-Open No. 61-207452 Japanese Patent Laid-Open No. 1-144434 Japanese Patent Laid-Open No. 4-108837 JP 10-36703 A JP 2005-272734 A

  The above-mentioned carbon black shows a significant effect on the technical problem of achieving both wear resistance and low heat build-up, but is sufficient for both wear resistance and fatigue resistance, particularly elongation characteristics. The present situation is that the improvement effect is not obtained. In view of the current situation, the object of the present invention is to provide a carbon black production method capable of achieving both wear resistance and low heat build-up for use in tire tread rubber blending, and maintaining a higher level of fatigue resistance. An object of the present invention is to provide a carbon black produced by the production method, a rubber composition using the carbon black, and a tire using the composition as a constituent member of a tread portion.

  The inventors of the present invention, that is, the physicochemical characteristics of carbon black as a filler capable of achieving both wear resistance and low heat build-up at the time of rubber compounding and maintaining higher fatigue resistance than before. As a result, the degree of connection of carbon black particles, particularly the compressed DBP absorption (24M4DBP) evaluated by the liquid absorption after compression treatment is high, and as a result, The fact that carbon black having a characteristic that the amount of hydrogen present on the surface of the carbon black is lower than the conventional one is suitable is the basis for producing the present invention.

  That is, the present inventors examined various processes for a method of producing carbon black having the above characteristics, and in particular, a reaction of a pyrolysis reaction (including a partial incomplete combustion reaction) of raw material oil in the carbon black production method. The inventors studied diligently about the effects of reaction rate and thermal history in the initial stage, that is, the stage of carbon black nucleation. As a result, by controlling the combustion gas flow rate at the feedstock introduction position, the residence time until the reaction temperature peak of the feedstock pyrolysis reaction, and the total heat history (exposure amount) of the feedstock pyrolysis reaction, the structure is increased. And a low hydrogen content at the same time, a method for producing carbon black that can simultaneously maintain wear resistance and low heat build-up for tire tread rubber blending and maintain high fatigue resistance, especially tensile properties. As a result, the present invention has been completed.

The first aspect of the present invention uses a carbon black production apparatus comprising a high-temperature combustion gas production zone, a reaction zone, and a reaction stop zone, generates high-temperature combustion gas by combustion of hydrocarbons in the high-temperature combustion gas production zone, and then continues to the reaction zone. Reaction is achieved by spraying feedstock into the high-temperature combustion gas stream at the upstream end, forming a reaction gas stream containing carbon black by a thermal decomposition reaction, and then introducing a quenching refrigerant into the reaction gas stream in the reaction stop zone. In a method for producing carbon black comprising quenching a gas flow to terminate the reaction, the combustion gas flow velocity at the feedstock introduction position is v _o [m / s], and the pyrolysis reaction temperature of the feedstock from the feedstock introduction position. the residence time to peak t _{o [s],} the residence time of the feedstock introduction position to the quench position t _{r [s],} quenched from the raw material oil introducing position Of the average value of the reaction temperature as _{T r [℃], v o} , t o, the following formula (i) in relation to a numerical value of _{t r,} and _{T r,} control under conditions that satisfy (ii) and (iii) The present invention relates to a method for producing carbon black. [S] indicates a unit of time, second.
(I) 30 ≦ v _o ≦ 110 [m / s]
(Ii) 0.0019-0.000015 * _vo- 0.0000000026 * CTAB
Specific surface area [m ² / g] ≦ t _o ≦ 0.0017 [s]
(Iii) 50 ≦ t _r × T _r ≦ 90 [° C. · s]
The second aspect of the present invention relates to a carbon black obtained by the production method described in claim 1.
3rd of this invention is related with the rubber composition which mix | blended the carbon black described in Claim 2.

Hereinafter, the present invention will be described in more detail.
In the present invention, a general carbon black production apparatus comprising a high-temperature combustion gas production zone, a reaction zone, and a reaction stop zone, for example, a production device disclosed in JP-A-2005-272729 (Applicant: Asahi Carbon Co., Ltd.) Can be used. More specifically, high-temperature combustion gas is produced by combustion of hydrocarbons for fuel in the high-temperature combustion gas production zone, and then, raw material oil is sprayed into the high-temperature combustion gas stream in the reaction zone, and carbon black is produced by pyrolysis reaction. In the method for producing carbon black, comprising the reaction gas flow comprising, and then quenching the reaction gas flow in the reaction stop zone to terminate the reaction, the combustion gas flow velocity at the feedstock introduction position is expressed as v _o [m / s ], the residence time of the feedstock introduction position to the thermal decomposition reaction temperature peaks of the feedstock t _{o [s],} the residence time of the feedstock introduction position to the quench position t _{r [s],} the stock oil introducing position the average value of the reaction temperature before quenching as _{T r} [° C.], the following formula (i) with respect to _{v o, t o, t r} , T r of the parameters, the condition of (ii), (iii) By controlling the production conditions to add, the amount of carbon black nuclei generated at the initial stage of the pyrolysis reaction is suppressed to reduce the amount of hydrogen present on the carbon black surface, and the degree of connection of the carbon black particles By giving a sufficient thermal history to develop a certain structure, it is possible to produce a carbon black that simultaneously imparts both high structure and low hydrogen content properties.
(I) 30 ≦ v _o ≦ 110 [m / s]
(Ii) 0.0019-0.000015 * _vo- 0.0000000026 * CTAB
Specific surface area [m ² / g] ≦ t _o ≦ 0.0017 [s]
(Iii) 50 ≦ t _r × T _r ≦ 90 [° C. · s]
Further, by blending the carbon black obtained by this method, it is possible to obtain a rubber composition that achieves both wear resistance and low heat buildup and maintains fatigue resistance.

In the equation (i), v _o is the combustion gas flow velocity at the feedstock introduction position and needs to be in the range of 30 [m / s] to 110 [m / s]. The combustion gas flow velocity at the feedstock introduction position can be controlled by either changing the flow rate of the generated combustion gas or changing the cross-sectional area of the feedstock introduction position. When the flow rate at the raw material oil introduction position is lower than 30 [m / s], the flow rate becomes slow, so that the mixing of the raw material oil and the high-temperature combustion gas becomes insufficient, and the productivity of carbon black decreases. Further, when the flow rate at the feedstock introduction position is higher than 110 [m / s], the life of the refractory covering the inside of the reaction apparatus is remarkably reduced, so the control is performed within this range. A more preferable flow rate range is 60 [m / s] to 100 [m / s].

In the formula (ii), t _o is the residence time (seconds) until the temperature peak in the pyrolysis reaction of the feedstock oil,
[0.0019-0.000015 × _vo −0.0000000026 × CTAB specific surface area [m ² / g]]
It is important to control within the range of not less than the numerical value calculated in (1) and 0.0017 seconds or less. By controlling t _o within the above range, the amount of carbon black nucleation in the initial stage of the pyrolysis reaction of the raw material oil can be suitably maintained, and both a low hydrogen content and a high structure can be achieved.
t _o can be controlled by using any method of changing the flow rate of the combustion gas, changing the amount of fuel, changing the cross-sectional area at the feedstock introduction position, or a combination thereof. Reducing the combustion gas flow, reducing the amount of fuel, by increasing the cross-sectional area of the feedstock introduction position, it is possible to lengthen the t _o. t _o [0.0019−0.000015 × v _o −0.000000026 × CTAB specific surface area [m ² / g]]
Below, the carbon black nucleation in the pyrolysis reaction of the feedstock is too fast and a large amount of nuclei are produced, making it difficult to reduce the hydrogen content and increase the structure.
When t _o exceeds 0.0017 [s], the pyrolysis reaction of the feedstock does not proceed sufficiently, making it difficult to sufficiently reduce the hydrogen, and the conversion rate from the feedstock to carbon black (yield) ) Decreases.

In the equation (iii), the coefficient [t _r × T _r ] value represents the total heat history received up to the reaction stop position in the incomplete combustion reaction of the feedstock oil, and is from 50 [° C. · s] to 90 [° C. · s]. Is preferred. [T _r × T _r] value 50 [℃ · s] If less than the insufficient thermal decomposition reaction of the raw material oil, low hydrogenation is difficult. Further, when the [t _r × T _r ] value exceeds 90 [° C. · s], it is necessary to greatly reduce the amount of combustion gas, and the production amount is reduced due to the reduction in the amount of feedstock introduced. A more preferable total heat history is between 50 [° C. · s] and 80 [° C. · s].

The carbon black production parameters used in the present invention, v _o , t _o , _tr and T _r are defined as follows.
v _o is the flow velocity in the standard state of the combustion gas flow at the feedstock introduction position,
v _o = (combustion gas flow rate [kg / h]) / (combustion gas standard density [kg / m ³ ])
× Cross sectional area [m ² ] × 3600 [s / h] at the position where the feedstock oil is introduced
Is calculated by Here, the density of the combustion gas standard state is the density of the combustion gas temperature at 0 ° C. and 1 atm. Nitrogen is 1.25 [kg / m ³ ], oxygen is 1.43 [kg / m ³ ], dioxide Carbon has a density of 1.98 [kg / m ³ ], oil fuel is assumed to produce stoichiometric carbon dioxide and water, and excessively introduced air (composition is nitrogen 79 and oxygen 21). ) is assumed to be present as it is, the amount of water assuming negligible since less calculated from the combustion gas composition was calculated v _0.
t _o Although it is the residence time of the feedstock oil introduction position in the thermal decomposition reaction of the feedstock to the pyrolysis reaction temperature peaks of the feedstock, the thermal decomposition reaction of the carbon black is a reaction of a few tens of milliseconds from a few milliseconds Therefore, it is difficult to detect the reaction temperature peak of the thermal decomposition reaction. In the present invention, therefore, it was calculated t _o from the fluidized combustion numerical analysis. For numerical analysis, a RANS (Reynolds Average Navier-Stokes) model is used, evaporation of the feedstock is performed using the Longwell equation, an incomplete combustion reaction is performed using a vortex dissipation model (Eddy Breakup model), and the turbulent time scale τ is It was calculated t _o with τ ₌ C τ × (feedstock nozzle diameter / material oil spray rate). Here, _Cτ is a correction coefficient of the turbulent flow time scale caused by the feedstock introduction, and the correction coefficient is expressed by an empirical formula of the combustion gas velocity and the feedstock amount derived from the spray flow experiment,
C τ ₌ 26.9 × (excess air ratio _[%]) / v 0 -0.0287 × (feedstock amount [kg / h]) + 23.5
(Excess air ratio [%]) = (1−air amount [kg / h] /15.58× (fuel amount [kg / h])) × 100
_Was used to calculate to.
_tr is the residence time from the feedstock introduction position to the reaction stop position,
_tr = (volume of the reactor from the raw material introduction position to the reaction stop position [m ³ ]) /
(Reaction gas flow rate [m ³ / s])
Is calculated by Further, T _r is the average reaction temperature in the reaction furnace.
The meaning of each parameter is as shown in FIG. In FIG. 5, the average temperature means a temperature corresponding to a straight line in which the areas of the plus part and the minus part of the temperature curve from the feedstock introduction position to the reaction stop position are equal. When a plurality of feedstock introduction surfaces, for example, 8A and 8B are used, each numerical value is calculated based on 8B of the feedstock introduction surface on the upstream side.

  The carbon black obtained in the present invention is a diene synthetic rubber such as polybutadiene rubber, styrene butadiene rubber, isoprene rubber or butyl rubber according to a conventional method, natural rubber, or one or more of the diene synthetic rubber and natural rubber. It can be used in combination. In the carbon black obtained in the present invention, the surface hydrogen content was reduced, so that the chemical bond between the carbon black surface and the rubber molecules when blended in the rubber was suppressed, and as a result, the elongation characteristics of the rubber were improved. In addition, by increasing the 24M4DBP characteristics of carbon black, it is possible to increase the physical reinforcing properties when blended with rubber, thereby obtaining a rubber composition having both wear resistance and fatigue resistance. it can. The blending ratio of carbon black is preferably set to 20 to 100 parts by weight with respect to 100 parts by weight of the rubber component. If the blending ratio of the carbon black is less than 20 parts by weight, sufficient wear resistance cannot be imparted to the blended rubber, and if it exceeds 100 parts by weight, the viscosity of the blended rubber will increase and the kneading processability will deteriorate. . At the time of blending, it is kneaded with vulcanizing agents, vulcanization accelerators, vulcanization accelerating aids, anti-aging agents, softeners, plasticizers, and other necessary components, and vulcanized to provide wear resistance and low heat build-up. Thus, it is possible to obtain a rubber composition suitable for a tire tread that can satisfy both of the above and can maintain fatigue resistance, particularly tensile properties.

  By applying the production method of the present invention, it has become possible to obtain carbon black that simultaneously satisfies the physicochemical properties of a high structure and low hydrogen content of carbon black. In addition, the rubber composition obtained by blending the carbon black obtained in the present invention has both wear resistance and low heat build-up, and can maintain fatigue resistance, particularly elongation characteristics. It can be preferably used.

  EXAMPLES Next, although an Example and a comparative example are shown and this invention is demonstrated further in detail, this invention is not limited at all by these examples.

Carbon blacks of Examples 1 to 5 and Comparative Examples 1 to 5 were produced using the carbon black reactor 1 shown in FIGS. 1 and 2.
FIG. 1 is a longitudinal front explanatory view of an apparatus used in the present invention.
2 is a cross-sectional view taken along the line AA in FIG.
In FIG. 1, each zone of the carbon black production furnace is divided into
High-temperature combustion gas generation zone: Reaction zone from upstream end of reactor to feedstock oil introduction position (8B in FIG. 1) Reaction zone: Reaction stopband from feedstock oil introduction position to reaction stop quench water pressure injection means installation position (e in FIG. 1) ... It means the downstream side from the installation position (e in FIG. 1) of the quench water injection spray means for stopping the reaction. Therefore, the space of each zone can vary depending on the feed oil introduction position and / or the quench water injection spraying apparatus installation position used for stopping the reaction.
The carbon black production apparatus 1 rectifies the oxygen-containing gas introduced through the oxygen-containing gas introduction pipe 3 provided on the outer periphery of the reactor head inside the combustible fluid introduction chamber (inner diameter 450 mmφ, length 400 mm) 2. A cylinder for introducing an oxygen-containing gas (inner diameter 250 mmφ, length 300 mm) 4 having a current plate 5 and a fuel introduction device (not shown) through a fuel oil (LPG) introduction pipe 6 at the center axis thereof, 2 is a converging chamber (upstream end inner diameter 370 mmφ, downstream end inner diameter 80 mmφ, convergence angle 5.3 °) 7 which is gradually converged, and the downstream side of the converging chamber 7 is an 8B plane shown as an example in FIG. The four raw oil spray ports (8B-1, 8B-2, 8B-3, 8B-4) are provided on the same plane to form four separate flat feed oil spray ports (8A to 8D). including It has a raw material oil introduction chamber 9, and this downstream side is composed of a reaction continuation and cooling chamber (inner diameter 140 mmφ, length 4000 mm) 10 equipped with a plurality of quenching water injection spray devices (a to y) for stopping the reaction. A carbon black reactor 1 covered with a refractory was used. SAF grade carbon black was produced under the conditions shown in Tables 1 and 2 using LPG as the fuel and ethylene bottom oil as the feedstock.

Each manufacturing condition and control factor in Table 1 and Table 2 will be described in more detail.
Example 1 is longer dwell time t _o to the thermal decomposition reaction peak of the feedstock by reducing the fuel introduction amount than conventional conditions, carbon black nuclei generation amount in the thermal decomposition reaction of the raw material oil (less than a conventional ) In a suitable state, and the [t _r × T _r ] value representing the magnitude of the thermal history of the reaction product is controlled to the higher side by moving the reaction stop position backward. On the other hand, Comparative Example 1 is a conventional production method, and Comparative Example 2 is a production condition in which the reaction stop position is shifted backward from Comparative Example 1 and only the value of the thermal history of the reaction product is controlled to be high.
As is apparent from the comparison between Comparative Example 1 and Comparative Example 2 and Example 1, Comparative Example 2 in which only the thermal history is increased in the conventional method has a large amount of carbon black generation nuclei, so the hydrogenation is not sufficient, and 24M4DBP The characteristics were lowered and the two were in contradiction, but by applying the production method of the present invention, it was possible to reduce the hydrogen content while maintaining the 24M4DBP characteristics.
Comparative Example 3 is a production condition in which the [t _r × T _r ] value representing the magnitude of the thermal history of the reaction product is controlled to be less than 50 by moving the reaction stop position forward from Example 1. . As is apparent from a comparison of Comparative Example 3 and Example 1, [t _r × T _r] Low hydrogen content is not sufficient heat history for the reaction product when controlling smaller than 50 values and high 24M4DBP characteristics It turns out that coexistence of these is difficult.
Example 2 is longer t _o by reducing further fuel from Example 1, it is raised manufacturing conditions [t _r × T _r] By moving the quench located downstream direction.
Example 3 by reducing approximately 15% of the combustion gas flow from the first embodiment, a longer t _o, a manufacturing condition by increasing the [t _r × T _r]. A longer t _o, by increasing control of the [t _r × T _r], it is clear that it is possible to highly achieve both high 24M4DBP and low surface hydrogen content.
Example 4 is a production condition in which the productivity of Example 1 is taken into consideration, the combustion gas flow rate is increased, and the reaction stop position is moved further downstream. On the other hand, Comparative Example 4 is a condition in which the combustion gas flow rate of Comparative Example 2 is increased.
From Example 4, it is clear that a high 24M4DBP and a low surface hydrogen content can be achieved at a high level by controlling to the conditions described in the present invention even if the combustion gas flow rate is increased in order to increase productivity. Meanwhile, although the control longer _{t 0} than in Comparative Example 4 In Comparative Example 2, reaches the [0.0019-0.000015 × _v o -0.00000026 × CTAB specific surface area ^[m 2 / g]] In addition, since the residence time until the reaction peak is not sufficiently secured, the amount of carbon black generation nuclei is increased, and the reduction in the amount of hydrogen is not sufficiently achieved.
By the fifth embodiment of a longer t _o while reducing the v ₀ by changing the feedstock introduction position to the large upstream side of the cross-sectional area, moving the quench located downstream [t _r × T _r] This is a production condition with a higher value.
On the other hand, Comparative Example 5 is the preparation conditions long t _o while reducing the v ₀ by changing the raw material oil introducing position from the Comparative Example 1 on the upstream side.
In Comparative Example 5, which is a conventional method, the 24M4DBP characteristics are improved, but the hydrogen content is also high, and the reduction of the hydrogen content is not sufficiently advanced.
On the other hand, Example 5 in which the [t _r × T _r ] value is controlled to be high indicates that the characteristics of high 24M4DBP and low hydrogen content can be highly compatible.
Tables 1 and 2 show the physicochemical characteristics of carbon black produced under each of these production conditions.
FIG. 3 is a graph showing the correlation between the 24M4DBP characteristic values in Tables 1 and 2 and the hydrogen content. As is apparent from FIG. 3, it can be seen that the conventional manufacturing method is highly compatible with the characteristics of high 24M4DBP and low hydrogen content, which are in contradiction.

In addition, the measuring method of each characteristic is as follows.
1) CTAB specific surface area (CTAB): Measured by the method described in JIS K6217-3: 2001, and is expressed as a specific surface area (m ² / g) calculated from the amount of CTAB adsorbed per 1 g of sample.
2) 24M4DBP absorption (24M4 DBP): measured by the method described in JIS K6217-4: 2001, and expressed in cm ³ of dibutyl phthalate (DBP) absorbed per 100 g of sample.
3) Hydrogen content: The carbon black sample is dried in a constant temperature dryer at 105 ° C. for 1 hour, cooled to room temperature in a desiccator, 10 mg is accurately weighed, and crimped and tightly plugged into a tubular tube sample container made of tin. The amount of hydrogen gas generated when heated at 2000 ° C. for 15 minutes under an argon stream with a hydrogen analyzer (manufactured by Horiba, Ltd., EMGA621W) is displayed in parts per million (ppm) with respect to the sample.

Preparation of rubber composition and rubber performance test Each carbon black produced in the examples and comparative examples produced under the conditions shown in Tables 1 and 2 was kneaded using a Banbury mixer at the blending ratio shown in Table 3. Further, vulcanized rubber sample pieces were obtained by vulcanization at 145 ° C. for 30 minutes using a pressure vulcanizer. Using this vulcanized rubber sample piece, 300% tensile stress (M ₃₀₀ ), elongation at break (Eb), and wear resistance were measured, and the results are shown in Tables 4 and 5.

ＭＢＴＳ：ジベンゾチアジルジスルフィド
ＩＰＰＤ：Ｎ−フェニル−Ｎ′−イソプロピル−ｐ−フェニレンジアミン

MBTS: dibenzothiazyl disulfide IPPD: N-phenyl-N'-isopropyl-p-phenylenediamine

＊ 各特性の数字は、比較例１の数値を１００としたときの指数である
なお、ゴム性能特性の測定方法は下記の通りである。

* The number of each characteristic is an index when the value of Comparative Example 1 is 100. The method for measuring the rubber performance characteristic is as follows.

Tensile test _{(M 300, Eb): JIS} K6251: 2004 - was carried out by the method described in "Rubber, vulcanized or thermoplastic Determination of tensile properties." The test piece is dumbbell-shaped No. 3, measured at a measurement temperature of 25 ° C. and a tensile speed of 500 mm / min, and according to the eighth term, the stress at 300% elongation (M ₃₀₀ ) and the elongation at break (Eb) are calculated. did.
Abrasion resistance test: Using a Lambourn abrasion tester, the amount of wear loss of each test piece at a test load of 4 kg, a slip rate of 60%, and a measurement temperature of 25 ° C. was measured. The sex index was calculated. In addition, it is excellent in abrasion resistance, so that an index value is large.
Formula: Wear resistance index = (S / T) × 100
Here, S: Comparative standard (Comparative Example 1) Abrasion loss amount of test piece
T: Abrasion loss amount of each rubber specimen

  The numerical values in Examples 1 to 5 and Comparative Examples 1 to 5 shown in Table 4 and Table 5 are the rubber compositions obtained by blending the carbon blacks manufactured under the manufacturing conditions shown in Tables 1 and 2, It is a rubber performance characteristic represented by an index (comparative example 1 is set to 100) when Comparative Example 1 is used as a reference standard. FIG. 3 shows the relationship between 24M4DBP and hydrogen content in each example and comparative example. FIG. 4 is a diagram showing the correlation between Eb and wear resistance from the numerical values in Tables 4 and 5. As is apparent from Tables 4 and 5 and FIG. 4, the carbon black obtained in the present invention is highly compatible with the characteristics of high 24M4DBP and low hydrogen content. Maintaining elongation characteristics at break by suppressing physical bonding to the rubber composition by providing physical reinforcement (wear resistance) to the rubber composition by the feature of high 24M4DBP and low hydrogen content It can be seen that both are highly compatible. In other words, the carbon black obtained in the present invention has a fatigue resistance, particularly tensile properties (Eb), in which the conventional method has a trade-off between the wear resistance and the low heat build-up, and the performance is deteriorated. Carbon black that is highly maintained and suitable as a compounding agent for a tread rubber composition for truck and bus tires can be provided, and is useful as a filling material.

It is longitudinal section explanatory drawing of the apparatus used in this invention. It is sectional drawing in the AA arrow of FIG. It is a graph showing the relationship between hydrogen content and a 24M4DBP characteristic value in an Example and a comparative example. It is a graph showing the relationship between the abrasion resistance and fatigue resistance in an Example and a comparative example. It is a model figure showing the definition of various parameters used by the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Carbon black reaction apparatus 2 Flammable fluid introduction chamber 3 Oxygen containing gas introduction pipe 4 Oxygen containing gas introduction cylinder 5 Rectifier plate 6 Fuel oil spraying apparatus introduction pipe 7 Converging chamber provided with fuel introduction means 8A Raw material oil spraying port 8B Raw material Oil spraying port 8C Raw material oil spraying port 8D Raw material oil spraying port 9 Raw material oil introduction chamber 10 Reaction continuation and cooling chamber ay Rapid water injection spraying means

Claims (3)

Using a carbon black production apparatus comprising a high-temperature combustion gas generation zone, a reaction zone and a reaction stop zone, high-temperature combustion gas is generated by combustion of hydrocarbons in the high-temperature combustion gas generation zone, and then the high-temperature combustion gas at the upstream end of the reaction zone Raw material oil is spray-introduced into the stream, a reaction gas stream containing carbon black is formed by a pyrolysis reaction, and then a quenching medium is introduced into the reaction gas stream in the reaction stop zone to quench the reaction gas stream and react. In the method for producing carbon black, the combustion gas flow velocity at the feedstock introduction position is v _o [m / s], and the residence time from the feedstock introduction position to the pyrolysis reaction temperature peak of the feedstock oil is t. _{o [s],} the residence time of from the raw material oil introducing position until the reaction stop position t _{r [s],} from the raw material oil introduction position before the reaction termination of the reaction temperature flat Values as _{T r [℃], v o} , t o, t r, and the following equation with respect to numerical values of _{T r} (i), and wherein the controller controls under conditions satisfying the (ii) and (iii) A method for producing carbon black.
(I) 30 ≦ v _o ≦ 110 [m / s]
(Ii) 0.0019-0.000015 * _vo- 0.0000000026 * CTAB
Specific surface area [m ² / g] ≦ t _o ≦ 0.0017 [s]
(Iii) 50 ≦ t _r × T _r ≦ 90 [° C. · s]   Carbon black obtained by the production method according to claim 1.   A rubber composition containing the carbon black according to claim 2.

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