JP5291902B2 - Method for producing modified carbon black for rubber compound treated with aqueous solution of sulfur oxoacid and modified carbon black for rubber compound obtained thereby - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface-treated carbon black capable of simultaneously imparting low heat generation properties too while keeping wear resistance when blended in a rubber, and to provide its manufacturing method. <P>SOLUTION: In the method of manufacturing a modified furnace carbon black for rubber blend, the method is characterized in that the modification treatment is carried out in such a way that (a) the separated solid carbon black is added with a sulfur oxo acid and/or an aqueous solution of its salt and treated or (b) the solid carbon black under the drying process is added with a sulfur oxo acid and/or an aqueous solution of its salt and treated. The modified carbon black for rubber blend obtained by the above is also provided. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention provides a carbon black suitable for use in rubber compounding, particularly tire tread rubber compounding, which has low fuel consumption characteristics while maintaining excellent wear resistance by increasing the surface functional groups of carbon black, and a method for producing the same About.

  When carbon black is blended with rubber, it has the ability to improve mechanical properties such as reinforcement and wear resistance, so it is widely used in various automotive parts such as tires. Depending on the required performance, carbon black with various properties has been selected and widely used.

  In recent years, the required performance of rubber products has continued to improve, and as one of the demands, it is desired to provide a rubber composition that simultaneously satisfies the two contradictory properties of wear resistance and low heat build-up of the rubber composition. ing. There are many technical ideas for resolving this contradictory phenomenon, and conventional techniques having various features for the purpose of solving this problem have been proposed.

First, as one technical idea, by controlling various colloidal characteristics such as aggregate characteristics which are the minimum dispersion unit of carbon black compounded in rubber, both wear resistance and low heat build-up in compounded rubber characteristics are achieved. There are technologies aiming at this, and there are various inventions as examples of these.
I. Patent Document 1 (Applicant: Tokai Carbon Co., Ltd.)
A rubber composition for a large tire tread, comprising furnace carbon black having the following selective characteristics (1) to (5) in a ratio of 35 to 100 parts by weight with respect to 100 parts by weight of the rubber component. object.
(1) Nitrogen adsorption specific surface area: 135 to 150 m ² / g
(2) CTAB adsorption specific surface area: 130 to 140 m ² / g
(3) Compressed DBP oil absorption: 85 to 95 ml / 100 g
(4) Relationship between Dst mode diameter (most frequent value) and ΔDst (distribution width):
0.519 × Dst + 8.0 ≦ ΔDst ≦ 0.519 × Dst + 32.6
(5) Dp mode diameter (largest pore diameter between particles measured by DSC) and ΔDp (distribution width):
0.776 × Dp + 1.5 ≦ ΔDp ≦ 0.776 × Dp + 40.5
II. Patent Document 2 (Applicant: Tokai Carbon Co., Ltd.)
A carbon black having a nitrogen adsorption specific surface area of 50 to 160 m ² / g, a DBP absorption amount of 125 ml / 100 g or more, and a moisture adsorption amount (Wm) satisfying the relationship of the following formula (1):
Wm ≦ 0.0357 × B-1.357 (1)
Here, B is blackness.
III. Patent Document 3 (Applicant: Tokai Carbon Co., Ltd.)
In a characteristic region where the CTAB adsorption specific surface area is 40 (m ² / g) or more and the DBP absorption amount is 90 (ml / 100 g) or more, the compression electric specific resistance when pressurized at 4.92 MPa is 3.0 ×. Carbon black satisfying the relationship [B ≧ 0.58 × CTAB + 48] between 10 ⁻³ Ω · cm or more and the blackness (B) and the CTAB adsorption specific surface area.
IV. Patent Document 4 (Applicant: Mitsubishi Chemical Corporation)
CTAB specific surface area of 110 to 160 m ² / g, 24M4DBP absorption of 90 to 140 ml / 100 g, the true specific gravity value of carbon black satisfies the following formula (1), and the carbon black aggregate maximum frequency Dmod and its half-value width D1 / A carbon black characterized in that a ratio D1 / 2 of 2 / Dmod and a 75% frequency value D75 of the aggregate diameter satisfy the following formula (2).
(True specific gravity value) ≦ 0.0005 × (24M4DBP) +1.6957 (1)
D75 ≦ 33.333 × (D1 / 2 / Dmod) +81.667 Expression (2)
V. Patent Document 5 (Applicant: Mitsubishi Chemical Corporation)
The CTAB specific surface area is 110 to 160 m ² / g, the 24M4DBP oil absorption is 90 to 140 ml / 100 g, and the carbon black aggregate shape parameter circular regularity (λ1) satisfies the formula 1 and the intrinsic elliptical eccentricity (λ2). Carbon black characterized by
λ1 ≦ 0.00278 × (24M4DBP) +0.0778 (Formula 1)
λ2 ≦ −0.00444 × (24M4DBP) +0.750 (Expression 2)

  However, there is a limit to achieving the above-mentioned object by controlling the carbon black aggregate characteristics as described above, and it has been necessary to set a compromise for any of the characteristics.

  Another attempt to solve this problem by applying carbon black having a characteristic that the moisture adsorption amount is not more than a certain value is to reduce the amount of surface functional groups on the surface of carbon black. Interaction, i.e., reduced wear resistance.

  In addition to this, specific requirements based on other carbon black colloidal characteristics have been advocated, and this has been tried to be specified with various requirements, but it still has the trade-off between wear resistance and low heat build-up. This indicates that no carbon black has been found that gives a rubber composition that can satisfy both conditions.

Another technical idea is an attempt to solve this problem by using surface-modified carbon black that aims to improve the wear resistance and heat generation in a balanced manner by post-processing the generated carbon black. Such an invention is disclosed.
VI. Patent Document 6 (Applicant: Tokai Carbon Co., Ltd.)
A surface-modified carbon black characterized in that a vinyl polymer is chemically modified by cationic polymerization by reacting a vinyl monomer starting from a carboxyl group formed on the surface of carbon black by oxidation treatment.
VII. Patent Document 7 (Applicant: Tokai Carbon Co., Ltd.)
A modified carbon black obtained by reacting diazophenol obtained by diazotization of aminophenol with carbon black and chemically modifying the hydroxyl group on the surface of carbon black by diazo coupling.

  However, these post-treatments have the disadvantage that the former has a very long reaction time of 10 hours, and the latter requires the addition of a silane coupling agent when blending the treated carbon black into rubber. Both of these are disadvantageous and are not preferable for practical means.

  As for the other oxidation treatment of carbon black, for example, Patent Document 8 [Applicant: Snow Covering Research Group], Patent Documents 9 and 10 (all of which are applicants: Philips Petroleum Company), There are documents (for example, Non-Patent Document 1), which are already known. However, simply oxidizing carbon black improves the hysteresis characteristics, but remarkably decreases the reinforcing property, which is an important characteristic for compounded rubber compositions, so it can be used as it is for rubber compounding as described above. There is a disadvantage that it can not.

Japanese Patent Application Laid-Open No. 8-20674 JP 2002-146097 A JP 2003-292822 A JP 2001-139840 A JP 2000-319539 A JP 2002-322388 A JP 2001-139839 A Japanese Patent Publication No.33-2471 US Pat. No. 4,518,434 US Pat. No. 4,631,304 Carbon, Vol. 14, 163 (1976)

  An object of the present invention is to provide a surface-treated carbon black capable of simultaneously imparting low heat buildup while maintaining wear resistance during rubber compounding, and a method for producing the same.

In the first aspect of the present invention, a heavy feedstock is spray-introduced into a high-temperature gas stream generated by combustion of hydrocarbon fuel in a furnace coated with a refractory, and the heavy feedstock is incompletely burned or heated. A suspension stream containing carbon black is generated by decomposition, and then the suspension stream is cooled to separate solid carbon black, and water is added to the separated solid carbon black, granulated, and then water of the system is removed. In a method for producing a modified carbon black for rubber compounding that is removed and dried in a high temperature atmosphere,
(A) said the separated solids carbon black, concentrations Ru to added pressure to the aqueous solution of 2.0 to 20 wt% of Iouokiso acid,
Or (b) to said solid carbon black in the drying step, concentration Ru to added pressure to the aqueous solution of 2.0 to 20 wt% of Iouokiso acid,
Production of modified carbon black for rubber compounding, characterized in that the amount of sulfur oxoacid contained in carbon black after drying is 0.3 to 3.0% by weight in terms of sulfuric acid by performing a modification treatment Regarding the method.
The second invention relates to a method of manufacturing a rubber for a modified carbon black of claim 1 wherein said Iouokiso acid is sulfuric acid.
The third aspect of the present invention relates to a rubber-modified carbon black produced by the production method according to claim 1 or 2 .
The fourth aspect of the present invention is a characteristic obtained by the reforming treatment, wherein the increase rate of the ratio of nitrogen adsorption specific surface area / iodine adsorption amount (km ² / kg) before and after the treatment is 105 to 130%, and nitrogen The modified carbon black for rubber compounding according to claim 3 , wherein the rate of increase in the ratio (-) of the adsorption specific surface area / CTAB adsorption specific surface area is 101% or less.
The fifth aspect of the present invention is a rubber composition which is a characteristic at the time of rubber compounding, wherein the rubber composition after treatment has a wear resistance index of 100 or more with respect to an untreated compound and a rebound resilience index of 103 or more. The modified carbon black for rubber compounding according to claim 4 , which gives a product.

  As shown in FIG. 1, the outline of the carbon black production process includes a reaction process for generating carbon black in a reaction furnace, a granulation process performed in a granulator, and a drying process performed in a dryer. As shown in FIG. 1, the raw material oil is sent from a tank to a reaction furnace for producing carbon black via an oil preheater, where the raw material oil is thermally decomposed to form a gas suspension stream containing solid carbon black. The gas suspension is cooled by adding water as a cooling medium to stop the crystal growth reaction on the carbon black surface. The gas suspension is then sent to a back filter to recover the solid carbon black. Solid carbon black is separated and collected by a filter made of glass fiber or the like in the back filter. This solid carbon black is kneaded with water in a granulator to obtain carbon black particles having a diameter of about 1 mm. The resulting carbon black granules are still quite hot due to residual heat in the drying process, so they are usually moved to a higher position by a bucket elevator for cooling and distribution to the product tank, passed through the magnetic separator and moved to the product tank. Store.

In the granulation step, granulation is usually performed using water, but the component added at this time is usually only a hardness modifier. The addition of "aqueous solution of Iouokiso acid" in the present invention is characteristic of, the form,
The use of "aqueous solution of Iouokiso acid" as granulation liquid in (a) granulating step
Or
(B) during the drying process is preferably carried out either in the form of spray addition of "aqueous solution of Iouokiso acid" in the process the second half of the drying process.
The latter method is more desirable in consideration of the possibility of equipment corrosion of dilute sulfuric acid aqueous solution and the possibility of component volatilization in the drying process.

A specific example of the sulfur oxo acid used in the present invention is sulfuric acid . Practically Ru using this aqueous solution. Usually, the solid carbon black is added to 0.1 to 20% by weight of the compound aqueous solution. The time from the addition to the drying of the carbon black may be only a short time, and it is generally preferable to complete the process in 10 to 15 minutes.

The concentration of the compound aqueous solution used for the treatment of the solid carbon black is preferably 0.1 to 20% by weight or 0.02 to 4N. When the concentration of the compound aqueous solution is 0.1% by weight or less, or 0.02 N or less, the contribution of the treated carbon black to the low heat build-up in the compounded rubber composition is too small, which is not preferable. In the case where the concentration of is 20% by weight or more in terms of sulfuric acid with respect to carbon black, or in the case of treatment with an aqueous solution of sulfur oxoacid having a concentration of 4N or more, the oxidizing action on carbon black particles becomes similar to that in nitric acid treatment. Therefore, the porosity due to surface erosion is increased, which leads to a tendency to deteriorate the wear resistance.

The use ratio of the sulfur oxo acid to the carbon black is preferably 0.3 to 3.0% by weight in terms of sulfuric acid when the carbon black is 100% by weight. When the amount is less than 0.3% by weight in terms of sulfuric acid, the contribution to the low heat build-up in the compounded rubber composition of the treated carbon black is not preferable because it is too small, and when the amount exceeds 3.0% by weight in terms of sulfuric acid In this case, the oxidizing action on carbon black is strengthened similarly to the nitric acid treatment, and the porosity due to surface erosion is increased. For this reason, the wear resistance tends to be lowered, which is not preferable.

<Measurement method of physicochemical properties>
The method for measuring the physicochemical properties of the carbon black particles of the present invention is as follows.

(1) Nitrogen adsorption specific surface area (N ₂ SA): Measured by the method described in JIS K6217-2: 2001, and expressed as a specific surface area (km ² / g) per unit weight.

(2) CTAB adsorption specific surface area: Measured by the method described in JIS K6217-3: 2001, and displayed as a specific surface area per unit weight (m ² / g).

  (3) Iodine adsorption amount (IA): Measured by the method described in JIS K6217-1: 2001, and expressed in grams (g / kg) of iodine adsorbed per unit weight (kg).

N ₂ SA / IA is used as an index of the increase rate of carbon black surface functional groups, and N ₂ SA / CTAB is used as an index of carbon black surface roughness, and the value is (number after treatment / untreated number) × 100 As an increase rate, it was used.

Examples of the method for quantifying oxygen-containing functional groups include quantification of total acidic group concentration with sodium hydroxide and quantification of strong acidic group concentration with sodium hydrogencarbonate. In the present invention, this is an oxidation treatment in a state containing oxo acid. Therefore, these methods are not appropriate methods because a neutralization reaction with acidic components (such as sulfate ions) contained in carbon black is predicted. Therefore, it quantified from the peak intensity of the CO ₂ and SO ₂ generated in GC-MS, was determined increment as oxygen-containing functional groups before and after treatment from this number (index).

The GC-MS conditions used as the functional group determination method are shown below.
Analytical instrument: Gas chromatograph: Agilent 6890N (Agilent technologies), column: Ultra Alloy-5 [Frontier Labs Co., Ltd.], mass spectrometer: Agilent 5975 inert (Agilent technologies), thermal decomposition apparatus: double shot pyrolyzer P-Y 202iD [Frontier Lab Co., Ltd.], trap device: Microjet Cryo Trap MJT-130E [Frontier Lab Co., Ltd.]
Measurement conditions: Thermal decomposition apparatus: 800 ° C., heating time: 3 minutes, carbon black amount: 5 mg, split ratio 100: 1, carrier gas and flow rate: He; 1 ml / min, oven temperature: 30 ° C./min Warm and hold at 320 ° C. for 5 minutes, MS interface: 320 ° C., detection mass range: 16-600 m / z

One of the characteristics of the modified carbon black for rubber compounding according to the present invention is that “the rate of increase in the ratio of nitrogen adsorption specific surface area / iodine adsorption amount (m ² / kg) before and after treatment is 105 to 130%” , value of iodine adsorption Yo as reforming process progresses decreases, one nitrogen adsorption specific surface area can be utilized as an indicator of the magnitude of the modification treatment effect because it increases the contrary, the numerical value is 105 When the ratio is less than %, the treatment effect is small, so that a problem that the contribution to low heat generation is too small occurs. The upper limit of the increase rate is 130%, and a value higher than this is not preferable because it tends to cause a decrease in wear resistance.

One of the characteristics of the modified carbon black for rubber compounding according to the present invention is that the ratio of increase in the ratio of nitrogen adsorption specific surface area / CTAB adsorption specific surface area (-) is 1% or less. When the porosity due to erosion of the black surface increases, the cross-sectional area of adsorbed nitrogen molecules (16.2 込め ² ) can enter the surface pores, but the cross-sectional area of large CTAB (61.6 Å ² ) is small. Since it cannot enter the pores, it can be used as an index indicating the porosity of the surface, and when it exceeds 1%, the problem arises that the porosity increases and the wear resistance decreases. Therefore, the smaller the increase rate, the better. The lower limit of the increase rate is 0% without change.

The present invention, as an oxidizing agent for oxidizing the particle surface of carbon black, select Iouokiso acid, by using, as to minimize the increase of pores in the surface while increasing the surface functional group of carbon black particles As a result, the carbon black particles of the present invention can simultaneously achieve low heat buildup while maintaining wear resistance when blended with rubber, and also exhibit an effect of 103% or more in rebound resilience.

EXAMPLES Next, an Example is shown and this invention is demonstrated further in detail . In this example, an ISAF grade grade carbon black (trade name: Asahi # 80) was produced using the carbon black production apparatus described in Japanese Patent No. 2931117 filed by the present applicant. This carbon black had basic characteristics of a nitrogen adsorption specific surface area of 118 (m ² / g), iodine adsorption amount 119 (mg / g), and DBP absorption amount 114 (ml / 100 g).
A heavy raw material oil is introduced into a furnace maintained at a high temperature, carbon black is generated by incomplete combustion or thermal decomposition of the raw material oil, and a high-temperature gas stream containing carbon black is cooled and then a solid-gas collecting and separating device ( Carbon black is separated by a bag filter, and wet pellets with a moisture content of 100% ± 10% are usually added to the separated carbon black by adding a granulating liquid (optionally containing granulating additives). Is adjusted in a pin type granulator, and then introduced into a drier in which the atmospheric temperature is maintained at 150 to 230 ° C. to perform dehydration to obtain a bead-like product. In the carbon black production process, the dilute sulfuric acid aqueous solution was added by spraying the sulfuric acid component-containing aqueous solution in the latter half of the process in the drying process.

<Addition of sulfuric acid aqueous solution in the second half of the granulation process>
An ISAF-grade carbon black was produced under the same production conditions as in Production Example 1-2 on page 8 of the specification of Japanese Patent No. 2931117 [Feed oil discharge amount: 503 l / hr, fuel oil supply amount: 97 l / hr, carbon black Conversion yield: 50% (270 kg / hr)].
In addition, as solid carbon black, it is desirable to process with respect to the grade in which reinforcement performance is generally calculated | required, ie, HAF-SAF grade carbon black.
The produced ISAF grade carbon black was collected and separated, and then introduced into a granulator, and 260 l / hr of granulation water [without additives: water content 96% (granulation water weight / carbon black weight) × 100 ] Was added to prepare bead-like carbon black.
This bead-like carbon black was introduced into a rotary drum dryer having an atmospheric temperature of 220 ° C., and the residence time of the bead-like carbon black in the dryer was controlled to be about 1 hour.
9.5 wt% (2 N) of dilute sulfuric acid 40 l / hr (dried carbon black) to bead-like carbon black being dried by a conduit provided with a nozzle at the tip of the rotary drum dryer from the outlet opening side into the dryer 1.4% by weight sulfuric acid) was introduced by spraying from a position 1/4 of the long axis of the dryer.
The water content of the bead-like carbon black after the sulfuric acid treatment introduced by spraying was 0.5%.
The liquid volume introduced into the same rotary drum dryer is constant, the sulfuric acid concentration is 2% by weight (0.3% by weight sulfuric acid with respect to the dry carbon black), and the 5% by weight sulfuric acid aqueous solution (0. 7% by weight sulfuric acid) and 20% by weight sulfuric acid aqueous solution (3.0% by weight sulfuric acid with respect to dry carbon black) were obtained.
These treated carbon blacks were run no. 1 to Run No. 1 4 is referred to.

  Further, the atmospheric temperature in the dryer is preferably controlled in the range of 150 to 230 ° C., and if it is 230 ° C. or higher, the oxygen-containing surface functional groups and sulfur-containing groups may be eliminated from the carbon black surface, thereby reducing the treatment effect. In addition, when the temperature is 150 ° C. or lower, moisture contained in the bead-like carbon black particles may remain within a predetermined time, which is not preferable.

  As a comparative example, an example in which no addition (0%) of sulfuric acid to the carbon black to be introduced and sprayed into the rotary drum dryer was added (0%). 5. As an example of excessive addition, an example of treatment with a 35 wt% sulfuric acid aqueous solution (5.2 wt% sulfuric acid with respect to dry carbon black) Run No. 5 It was set to 6.

  Next, as a treating agent for treating carbon black, instead of sulfuric acid aqueous solution, nitric acid known as an oxidizing agent that has been conventionally used is 1.0% by weight with respect to dry carbon black and has no oxidizing property. The acid, acetic acid, was treated with 4.0% by weight of dry carbon black. 7 and Run No. It was set to 8.

  Each Run No. described above. Tables 1 and 2 show the respective treatment conditions and the physicochemical characteristics of the obtained treated carbon black.

注：１）カーボンブラックに対する処理成分の１００分率（重量％）
２）コントロール（Ｒｕｎ Ｎｏ．５）を１００とした指数

Note: 1) 100% (% by weight) of processing ingredients relative to carbon black
2) Index with control (Run No. 5) as 100

<Rubber compounding characteristics>
The aforementioned Run No. 1 to Run No. 1 4 and Run No. 4 5 to Run No. A rubber composition was prepared using the carbon black of Comparative Example 8 with the formulation of each component shown in Table 3, and vulcanized at 145 ° C. for 30 minutes using a pressure vulcanizer to obtain a vulcanized rubber. It was. Various rubber performance tests were conducted on this vulcanized rubber, and the results are shown in Tables 4 and 5. The performance test of the vulcanized rubber composition was measured as follows.

<Abrasion resistance evaluation of vulcanized rubber>
The amount of loss due to wear of each test piece was measured using the improved lambourne wear tester of JIS K6264: 2005, item 9, and the wear resistance index was calculated by the following formula. In addition, it means that it is excellent in abrasion resistance, so that an index value is large.
Formula: Abrasion resistance index = (S / T) × 100
S: Abrasion loss amount of a comparative control standard (Run No. 5) test piece T: Abrasion loss amount of each rubber test piece

<Exothermic evaluation of vulcanized rubber>
The rebound resilience of each test piece was measured using the Lübke-type rebound resilience test apparatus described in item 4 of JIS K6255-1996. In addition, the rebound resilience of the comparative reference (Run No. 5) test piece was expressed as an index with 100 as the resilience. The larger the index value, the higher the resilience and the better the low heat buildup (the lower the better).

From the results of carbon black treatment conditions, physicochemical properties, and rubber composition performance evaluation shown in Tables 1, 2, 4, and 5, the effects of the present invention are as follows.
In Examples 1 to 4 subjected to the treatment in the present invention, it was confirmed that the impact resilience was improved while maintaining the wear resistance performance as compared with Comparative Example 1.
It is this rubber characteristic that shows
(1) Sulfur oxo acid bonded to or incorporated into carbon black acts as an unsaturated bond of the polymer skeleton to form a network, thereby improving the mechanical properties of the rubber composition.
(2) Sulfur oxo acid acts on the vulcanizing agent and vulcanization accelerator added to the rubber composition, and contributes to improving the performance of the vulcanizing agent and vulcanization accelerator.
(3) The dehydration action of sulfur oxo acid reduces the cohesive force between carbon blacks caused by modification of the functional groups on the surface of carbon black (formation of lactone groups or carboxylic acid anhydrides), and the dispersibility of carbon black is reduced accordingly. Improve,
Factors such as are considered, but it is not clear at present.

Further, in Comparative Example 2 treated with an aqueous solution having a sulfuric acid concentration exceeding the range of the present invention and Comparative Example 3 treated with nitric acid, which is a conventional knowledge, an improvement in impact resilience was seen, but reinforcement Sexual decline was observed. This is presumably because the N ₂ SA / IA ratio of the characteristics shown in Table 2 is high, that is, the carbon black surface porosity is large, and the surface is partially eroded by oxidation.
In the acetic acid-treated product (Run No. 8) having no oxidizing property, no effect was seen in both wear resistance and impact resilience.

As a chemical for treating carbon black, a 2N sulfate (sodium sulfate decahydrate) aqueous solution is used and treated in the same manner as described in the first to third phrases in [0030] to obtain modified carbon black. It was. A rubber composition was prepared from this treated carbon black at a blending ratio shown in [0040] Table 3. Wear resistance and impact resilience were measured using 5 as a comparative control (100), and values of 100 and 108 were shown, respectively.
Although the effect seems to be slightly smaller than the case of dilute sulfuric acid from the concentration of the treated product, it was confirmed that the intended effect was exhibited.

  As described above, it is apparent that the carbon black treatment method disclosed in the present invention and the carbon black treated thereby have a great advantage over conventional products.

It is a figure which shows the general manufacturing process of carbon black.

Claims (5)

A heavy feedstock is sprayed into a high-temperature gas stream generated by the combustion of hydrocarbon fuel in a furnace covered with refractory, and carbon black is suspended by incomplete combustion or thermal decomposition of the heavy feedstock. A turbid stream is generated, and then this suspension stream is cooled to separate solid carbon black, water is added to the separated solid carbon black, granulated, and then water in the system is removed under a high temperature atmosphere and dried. In the manufacturing method of the modified carbon black for rubber compounding ,
(A) said the separated solids carbon black, concentrations Ru to added pressure to the aqueous solution of 2.0 to 20 wt% of Iouokiso acid,
Or (b) to said solid carbon black in the drying step, concentration Ru to added pressure to the aqueous solution of 2.0 to 20 wt% of Iouokiso acid,
Production of modified carbon black for rubber compounding, characterized in that the amount of sulfur oxoacid contained in carbon black after drying is 0.3 to 3.0% by weight in terms of sulfuric acid by performing a modification treatment Method. The process according to claim 1 for blending with rubber modified carbon black, wherein the Iouokiso acid is sulfuric acid. A modified carbon black for rubber compounding produced by the production method according to claim 1 or 2 . With the characteristics obtained by the reforming treatment, the increase rate of the ratio of nitrogen adsorption specific surface area / iodine adsorption amount (km ² / kg) before and after the treatment is 105 to 130%, and the nitrogen adsorption specific surface area / CTAB adsorption ratio The modified carbon black for rubber compounding according to claim 3 , wherein the increase rate of the surface area ratio (-) is 101% or less. In characteristic during rubber compounding, the rubber composition after the treatment, the abrasion resistance index relative to untreated formulation is 100 or more, and impact resilience index gives a rubber composition exhibiting 103 or more numeric claim 4, wherein modified carbon black for rubber compounding.

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