KR930002553B1 - Carbon black for rubber composion - Google Patents

Abstract

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Description

Rubber Black Carbon Black

1 is a schematic diagram of an oil furnace having a Y-phase structure used for producing carbon black of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to carbon black for rubber compounding, and more particularly, to carbon black suitably blended with a rubber used in a tread member of a passenger tire, which requires high wear resistance and resilience. The rubber material constituting the treader of the passenger tire is required to have a dynamic performance that suppresses the loss of driving energy such as high resilience and low heat generation.

So to use the dynamic performance, by the properties of the carbon black compounded in the rubber, to improve the large (BET specific surface area (N ₂ SA) is small), the particle size of carbon black is to be valid.

However, this carbon black exhibits a betrayal behavior on the rubber reinforcement surface and results in a significant retreat of the most important wear resistance as a tire tread.

For this reason, conventionally, the passenger tire tread has a BET specific surface area of 85 m ² / g or more in combination to ensure wear resistance, and at the same time, aggregate size distribution width as much as possible. By selecting and using the carbon black of this wide characteristic, the method of praying for improvement of an elastic surface was taken.

However, the use of carbon black in the particle size range of less than 85 m ² / g BET improves the resilience but greatly reduces the abrasion resistance, resulting in a problem that the performance of the passenger xk ear as a tread member cannot be satisfied. .

An object of the present invention is to solve the above problems and to provide a carbon black which can simultaneously give a high degree of wear resistance and rebound elasticity to a compounded rubber in a particle size region having a BET specific surface area of 84 m ² / g or less.

The object of the present invention is that the BET specific surface area (N ₂ SA) is in the range of 65 to 84 m ² / g, the a value obtained by the following formula is 270 or more, and the BET specific surface area (N ₂ SA) / oxo adsorption amount (IA). Is achieved by carbon black satisfying the characteristic requirements of 1.10 to 1.35.

×10^-6 a = (24M4DBP) ² × (Blankness / IA) ² ×

× 10 ^-6

Among the properties of the carbon black according to the present invention, the particle size range of BET specific surface area (N ₂ SA) 65 to 84 m ² / g gives resilient elasticity and low calorificity suitable for compounded rubber, while suppressing the extreme wear resistance retreat. It is a prerequisite for this.

In addition to this prerequisite, the value of a is held at 270 or more, which is larger than that of conventional carbon black, and the N ₂ SA / IA ratio is adjusted to 1.10 to 1.35 to maintain an appropriate level of wear resistance and It is possible to effectively prevent the deterioration of characteristics.

The characteristic item of the carbon black of the present invention is a value measured by the following method.

(1) BET specific surface area (N ₂ SA)

According to ASTM D3037-78 "Standard Method for Inspecting Carbon Black Surface Area by Nitrogen Adsorption" Method B. The BET specific surface area (N ₂ SA) of IRB # 5 measured by this method is 80.3 m ² / g.

(2) 24M4DBP (compression DBP oil absorption)

According to ASTM D3493-79 "Carbon Black Dibutyl Phthalate Absorption of Compressed Samples",

(3) Blackness

0.500 g of a dry carbon black sample having a particle size of 149 µ or less is weighed, weighed and mixed with a drop of linseed oil on a glass plate. The paste is 25 × 5 times with a load of l5 lb on a Hoover type muller. The mixture is kneaded to form a thin film of sample carbon black paste on the glass plate surface. On the other hand, reflecting head # 3832A (Densicron A9155, reflectance photometer manufactured by Welch Scientific Co.) of Densicron A9155 was previously set on the thin film formed as described above with respect to reference sample IRB # 2, and was set to 50%. Confirm that the meter value at the time of moving at least three places becomes 49.5-50.5%. Next, place the head on a thin film of sample carbon black and read the meter value. The head is moved five places and the average value is calculated as the measured value.

However, T is the measured value of the sample carbon black, 100 is the blackness of the reference sample IRB # 2, and 50 is the set value of the reference sample IRB # 2 thin film.

(4) IA (oxo adsorption amount)

According to JIS K6221 (1975), Test Method for Rubber Carbon Black, in 6.2.1 Oil Absorption A Method. More specifically, 0.5 ± 0.005 g of dried carbon black sample was charged to a 200 ml Erlenmeyer flask equipped with a stopper, and 25 ml of 0.0473 N oxo solution was added to the flask described above. Shake at a rate of more than a minute. At that time, the carbon black sample was separated and the filtrate was titrated with 0.0394 N-sodium thiosulfate solution (a ml). An empty test was carried out in the same process as in (b ml). Oxo adsorption amount of the carbon black sample was calculated by the following equation.

Where IA: Oxo adsorption (mg / g)

W _D : Weight of dried carbon black (g)

V: amount of added oxo solution (ml)

N: Regulation diagram of oxo solution (0.047)

f: factor of oxo solution

(

Mode Diameter)(5)

(

Mode Diameter)

A dispersion of carbon black having a concentration of 50 mg / l of carbon black, mixed with a 20% ethanol aqueous solution containing a small amount of surfactant (dispersion medium), after drying according to JIS K6221 (1975) 6.2.1 Method A Prepare and disperse with ultrasonic wave sufficiently to obtain a sample liquid.

Meanwhile, the Disc Centrifuge device (manufactured by Joyceble UK) is set at a rotational speed of 8000 rpm, 10 ml of spin solution (2% aqueous glycerin solution) is added, and then 1m1 buffer solution (ethanol aqueous solution) is injected. .

는 얻어진 분포곡선에 있어 최대빈도(최대흡광도)의 스톡스 상당경(nm)을 나타낸다.Subsequently, 0.5 ml of the sample liquid is collected in a syringe, added to the spin liquid to start centrifugal sedimentation, and the recorder is operated at the same time to prepare an optical distribution curve of the aggregate stock diameter.

Represents the Stokes equivalent diameter (nm) of the maximum frequency (maximum absorbance) in the obtained distribution curve.

80nm이었다.In addition, ASTM D-24 Standard Reference Black C-3 (N234) was measured by this method.

80 nm.

Carbon black having the characteristics described above for the present invention was prepared as an oil furnace having a Y-phase structure as shown in the accompanying drawings, for example, according to the contents of Japanese Patent Laid-Open No. 59-49267. As described in the drawing, the oil furnace 1 constitutes two generators 2 and 2 ', and the generators 2 and 2' are concentrated in the main reaction zone 3. The generator 2 is composed of a high temperature heating duct 7 connected to the combustion chamber and the combustion chamber 4, and the generator 2 'is a high temperature heating duct 7' connected to the combustion chamber 4 'and the combustion chamber 4'. It consisted of Burners 5 and 5 'and raw material oil injection nozzles 6 and 6' were installed in each combustion chamber 4 and 4 ', and they were arranged coaxially with each other. The gas stream of the intermediate-generated carbon black formed in the combustion chamber 4 and the gas flow formed in the combustion chamber 4 'are simultaneously introduced into the main reaction zone 3 through the high temperature heating ducts 7 and 7' at high speed. It is introduced and collides with each other to obtain the desired carbon black. Reference numeral 8 is a spray nozzle for cooling water and 9 is a windbox.

At this time, the carbon black having the characteristics of the present invention can be obtained by controlling the conditions of the generators 2 and 2 'and the residence time of the generated carbon blacks.

Carbon black according to the present invention is blended into various synthetic rubbers or natural rubber components according to a conventional method.

에 의해 결정되는 a값을 종래 품종의 카본블랙보다 훨씬 높은 270이상으로 제어하되 N₂SA/IA비를 1.10∼1.35로 조정함에 의해 효과적으로 억제할 수가 있다.Therefore, the abrasion resistance retraction tendency due to the low BET specific surface area (N ₂ SA) is set within 65 to 84 m ² / g.

The a value determined by is controlled to 270 or more, which is much higher than that of the conventional varieties of carbon black, but can be effectively suppressed by adjusting the N ₂ SA / IA ratio to 1.10 to 1.35.

As a result, according to the carbon black of the present invention, carbon black having a BET specific surface area (N ₂ SA) of less than 85 m ² / g can be used to impart resilient elasticity and wear resistance suitable for rubber.

Therefore, by combining the carbon black of the present invention with the tread rubber of the passenger tire, etc., it is possible to effectively reduce the rolling resistance and reduce the fuel consumption during running.

[Example, Comparative Example]

As shown in FIG. 1, a combustion chamber having an internal diameter of 400 mm and a length of 800 mm (cone part 200 mm) having a combustion burner 5 and a raw material oil injection nozzle 6 mounted thereon through a wind box 9, 9 'at the head ( 4) Inner diameter of 650mm and 800mm in length, equipped with combustion burner (5 ') and raw material oil injection nozzle (6') with the first generating part equipped with pyrolysis conduit (7) with inner diameter of 80mm and length of 700mm A second generating section having a combustion chamber 4 'of a portion 200 mm) and a second generating section having a thermal decomposition conduit 7' having an inner diameter of 110 mm and a length of 1000 mm, and a rear end light portion 11 having a diameter of 300 mm and a length of 4000 mm; It was installed in an oil furnace of a Y-shaped structure in which the shear narrowing section 10 having an inner diameter of 135 mm and a length of 850 mm was converged to a front of the main reaction zone 3 with a piercing of 60 °.

As raw material oil, specific gravity (15/4 ° C) 1.0703, viscosity (Angler 40/120 ° C) 2.10, benzene insoluble content 0.03%, correlation coefficient (BMCI) 140, initial boiling point 103 ° C aromatic hydrocarbon oil, Hydrocarbon oil of specific gravity (15/4 degreeC) 0.903, viscosity (CST 50 degreeC) 16.1, xanthan powder 5.4%, sulfur content 1.8%, and a flash point of 96 degreeC was used.

Carbon black of this invention was manufactured using the above-mentioned reaction furnace using the raw material oil and the fuel oil, and applying the development conditions shown in Table 1.

TABLE 1

Various properties and calculated values of the carbon black produced in Table II are shown.

In addition, Run Nos. 5 to 8 shown as comparative examples in Table II are the same level as in Examples prepared by the prior art, and Run No. 9 is carbon black having a BET specific surface area (N ₂ SA) of 85 m ² / g or more. .

TABLE 2

×10^-6 a value = (24M4DBP) ² × (Blankness / IA) ² ×

× 10 ^-6

Next, the various carbon black of Table II was mix | blended with the styrene butadiene rubber (SBR) component with the compounding system shown in Table III.

TABLE 3

Various rubber properties were measured for the rubber composition obtained by vulcanizing the compound of Table III at a temperature of 145 ° C. for 50 minutes. The results are shown in Table IV, corresponding to the compounded carbon black Run No. of Table II.

In addition, the measuring method and measurement conditions of a rubber characteristic were based on what was described next.

(1) wear

A Lambbourn abrasion tester (mechanical slip mechanism) was used and measured under the following conditions.

Test piece: thickness 10mm, outer diameter 44mm,

Emery wheel: GC type, particle size 80, hardness H

Added Carborundum: Particle size 80 #, added amount about 9g / min

Relative slip rate between emery wheel and test piece: 24%, 60%

Test piece rotation speed: 535rpm

Test load: 4 kg

(2) exothermic degree

According to ASTM D623-78 (using Goodrich Flexometer).

(3) Others

According to JIS K6301 "Vulcan rubber rubber physical test method".

TABLE 4

Considering the results of Table IV together with the characteristics of Table II, when the BET specific surface area (N ₂ SA) of the applied carbon black is located at the same level, the rubber compositions according to the examples retained the same wear resistance as compared with the comparative examples. As a result, semi-elasticity and exothermicity, which are factors of dynamic performance, are much improved, and rubber performance is not affected by Run No. 9 with a BET specific surface area (N ₂ SA) of more than 85 m ₂ / g. have.

Claims (1)

The BET specific surface area (N ₂ SA) is in the range of 65 to 84 m ² / g, and a value obtained by the following formula is 270 or more and the ratio of BET specific surface area (N ₂ SA) / oxo adsorption amount (IA) is 1.10 to 1.35. Carbon black for rubber compounding. a = (24MDBP) ² × (Blankness / IA) ² ×

× 10 ^-6

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