KR100494216B1 - Process for preparing surface-treated carbon black and rubber composition - Google Patents

Abstract

The present invention relates to carbon black having silica attached to the surface, wherein the attached silica has a thickness of 0.1 to 20 nm and a width of 1 to 40 nm.

Description

Process for producing surface treated carbon black and rubber composition {PROCESS FOR PREPARING SURFACE-TREATED CARBON BLACK AND RUBBER COMPOSITION}

The present invention relates to a method for producing carbon black in which a silanol group is present on a surface by adhering silica to a surface thereof, and a rubber composition incorporating the carbon black, wherein the resulting rubber composition is suitably used for the production of tire treads or belts. .

Tan δ is an indicative of exothermicity when the vulcanized rubber composition containing reinforcing particles is subjected to repeated deformation. For example, in order to reduce the rolling resistance of the tire tread to achieve low fuel consumption, it is known that the tan δ of 50 to 70 ° C. should be made small. On the other hand, the braking characteristics and the like on the wet road surface tend to be larger in tan δ around 0 ° C. As a method of improving the temperature dependency of tan-delta, ie, making tan-delta of 50-70 degreeC small and tan-delta of 0 degreeC vicinity, trying to mix | blend silica as a filler is tried. For example, Japanese Unexamined Patent Application Publication No. H3-252433 describes mixing a silica and a silane coupling agent in the solution polymerization method SBR. In addition, Japanese Laid-Open Patent Publication No. 7-165991 discloses that as a silane coupling agent, particularly, a bifunctional one capable of reacting with silica and rubber is excellent.

This is because when the particles having silanol groups on the surface, for example, silica particles, are vulcanized by mixing with a silane coupling agent such as bis (3-triethoxysilylpropyl) -tetrasulfane in a diene rubber and vulcanized, It is known that rubber bonds chemically, thereby improving physical properties such as lowering of tan δ around 60 ° C. of the particle mixture vulcanized rubber composition and improved wear resistance.

However, when silica is blended as a filler, the temperature dependence of tan δ can be improved, but the silica filler has a problem in that it is difficult to disperse in rubber due to its strong magnetic cohesion and poor workability. In addition, since the expensive silane coupling agent must be added in an amount of 5 to 15% to silica, there is also a problem that the compound cost is high.

In addition, when the silane coupling agent having a sulfur atom as described above is added to the carbon black without blending the silica filler, tan δ around 60 ° C of the particle blend rubber composition may be considerably reduced. However, since the high modulus of elasticity (E ^* ) and dynamic modulus (E ') of the low temperature region (-10 to 0 ° C) and low torsion (0.1 to 1%) are high, there is a drawback that the braking characteristic is lowered.

On the other hand, it is proposed to surface-treat carbon black blended with a rubber composition with silica or silane. For example, Japanese Patent Application Laid-Open No. 53-100190 or Japanese Patent Laid-Open No. 61-291659 discloses a method of mixing an organic compound or an organometallic compound of silicon dissolved in a solvent or water with carbon black and drying it. As the silicone compound, dimethyl polysiloxane or silicone oil is used. Also, JP-A-56-38357 proposes a surface hydrophobized carbon black having a surface treated with a cyclic alkylpolysiloxane or a silicone compound. Japanese Laid-Open Patent Publication No. 58-125249 describes carbon black coated on the surface of a silane coupling agent dissolved in a solvent. JP-A-63-63755 proposes a method of precipitating amorphous silica on the surface of carbon black by dispersing carbon black in water and neutralizing sodium silicate with sulfuric acid. However, these methods are hardly said to be suitable for industrialization in terms of processes and economics such as removal, recovery or neutralization of solvents. Japanese Unexamined Patent Application Publication No. 4-233976 proposes to chemically modify carbon black with a specific organosilicon compound (specifically, a sulfur-containing silane coupling agent having a specific structure). However, this method also has a process and economic problem such as extraction operation or post-treatment for denaturation. Moreover, in the method of treating these carbon blacks with surface treating agents, such as a silica and a silane, it is also expected that a surface treating agent will not adhere uniformly enough to all the carbon black surfaces.

Disclosure of the Invention

MEANS TO SOLVE THE PROBLEM In view of the said subject, the present inventors provide the rubber composition which has the viscoelastic property (temperature dependence of tan-delta) of silica level, and improves the dispersibility and the processability of silica to the carbon black level, and mix | blended this The method of adhering silica to the carbon black surface was earnestly examined.

As a result, the surface treatment of carbon black is carried out by a specific method using a specific silicon-containing compound, so that silanol groups can be effectively and effectively present on the surface of the carbon black, and the surface treated carbon black is blended in this manner. One rubber composition has been found to exhibit excellent properties, leading to the completion of the present invention.

That is, the present invention comprises a mixture of surface treated carbon black and the surface treated carbon black, wherein the silane and / or polysiloxane, in which all organic groups are bonded to silicon via oxygen, is brought into contact with the carbon black surface at 200 ° C. or lower. In the rubber composition.

Since the silanol group can be introduced to the surface of the carbon black according to the present invention, physical properties such as reduction of tan δ around 60 ° C and improvement of abrasion resistance of the vulcanized rubber composition attempted by blending particles having silanol groups such as silica particles. The improvement can be achieved without mixing particles such as silica.

Moreover, the complex elastic modulus (E ^* ) and dynamic elastic modulus (E ') in the low temperature range (-10-0 degreeC) and low torsion (0.1-1%) similar to the case where the silane coupling agent which has a sulfur atom are mix | blended As a result, it is possible to solve the disadvantage that the braking characteristic is lowered.

In addition, according to the surface-treated carbon black obtained in the present invention, it is possible to improve the hard dispersibility and the hard workability, which are defects of silica, to the carbon black level. Therefore, according to the present invention, reinforcing particles having the advantages of silica and carbon black, that is, reinforcing particles having viscoelastic properties (temperature dependence of tanδ) at the silica level and improving the dispersibility and workability of the silica to the carbon black level, It becomes possible to provide the rubber composition which mix | blends this.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the transmission electron micrograph (2,000,000 times) which shows the carbon black with silica obtained in Example 8.

FIG. 2 is a diagram illustrating an EDX spectrum of part A in FIG. 1.

FIG. 3 is a diagram illustrating an EDX spectrum of part B in FIG. 1.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

First of all, carbon black as a raw material to be used for surface treatment in the present invention is not particularly limited. However, when blended with rubber, carbon black can be used in the rubber industry and is known in various types such as furnace black (ASTM D 1765). ), Channel black, thermal black, acetylene black and the like are preferable. In order to produce these raw carbon blacks, for example, in the case of the furnace black, a high aromatic heavy oil is introduced into a high temperature gas stream, which can be obtained by incomplete combustion or pyrolysis of the heavy oil.

In the present invention, carbon black is contacted with a specific silicon compound. That is, all organic groups are in contact with silane and / or polysiloxane which are bonded to silicon via oxygen.

Here, silane and / or polysiloxane in which all organic groups are bonded to silicon through oxygen means silane and / or (Si-O) in which hydrogen, alkyl group, vinyl group, phenyl group or other functional groups are bonded to Si through O. n is used as the main chain (the main chain may be branched or may form a ring), and Si refers to a polysiloxane in which hydrogen, an alkyl group, a vinyl group, a phenyl group, or other functional group is bonded via O.

Preferably, tetraalkoxysilane and / or polyalkoxypolysiloxane having C _1-4 alkyl group bonded to Si is used. The latter can be easily obtained as the former low condensate. As the latter, what is represented by following General formula (1) is mentioned, for example.

[Formula 1]

(RO) ₃ -Si-O- [Si (OR) _n -O _(3-n) ] _m R

N is 1 or 2, m is an integer of 0 or more, and R is a C _1-4 alkyl group which may be different from each other. The alkyl group may be substituted with hydrogen.

In particular, there is an oligomer which is a low-condensation product of tetramethoxysilane as R = CH _3- , and the amount of monomer (ie, tetramethoxysilane) contained in Mitsubishi Chemical Co., Ltd. product "MKC silicate MS51" is 1 It is preferable because it is less than% by weight, and therefore excellent in quality stability and safe in use because of less toxicity by monomers. In the present invention, silane and / or polysiloxane in which all of these organic groups are bonded to silicon via oxygen may be used as it is, but hydrolysis or condensation of hydrolyzed or hydrolyzed by adding water and a hydrolysis catalyst or the like to this may be used. Condensates may also be used.

As a hydrolysis-condensation product, "MKC silicate MS51SG1" (made by Mitsubishi Chemical Co., Ltd.) which hydrolyzed and condensed the oligomer of the said tetramethoxysilane in alcohol is mentioned, for example. This is preferably used because a large number of silanol groups are generated by hydrolysis.

Since these tetraalkoxysilanes and / or polyalkoxypolysiloxanes have a large number of alkoxy groups, adhesion to carbon black and generation of silanol groups are very excellent, thereby greatly improving the properties of the surface-treated carbon black obtained and the rubber composition formed by blending them. You can think of

Further, carbon black may be brought into contact with carbon black in which silane and / or polysiloxane in which all of these organic groups are bonded to silicon via oxygen are mixed with other organic components such as a silane coupling agent. In this case, the other organic component is preferably 50 parts by weight or less, preferably 20 parts by weight or less based on 100 parts by weight of silane and / or polysiloxane in which all organic groups are bonded to silicon via oxygen. As an organic component, various resin components other than various silane coupling agents are mentioned, What is necessary is just to select suitably, and to mix | blend with the said silane and / or polysiloxane.

Surface treatment of carbon black with silanes and / or polysiloxanes in which all organic groups are bonded to silicon via oxygen is carried out by contacting these compounds with carbon black at 200 ° C. or lower. When it exceeds 200 degreeC, the evaporation (gasification) of the silane and / or polysiloxane in which all the organic groups are couple | bonded with the silicon | silicone via oxygen is accelerated | stimulated, for example, a problem arises that the adhesion rate at spraying falls.

The amount of silane and / or polysiloxane in which all organic groups are bonded to silicon through oxygen is not particularly limited, but 0.1 to 50 parts by weight is usually used based on 100 parts by weight of carbon black. More preferably, it is 0.2-30 weight part. When the amount is too small, the effect of improving the temperature dependence of tan δ is small. On the contrary, when the amount is too large, the dispersion workability in the mixed dough is deteriorated and the cost is high.

The contact of silane and / or polysiloxane and carbon black, in which all of these organic groups are bonded to silicon via oxygen, is not particularly limited as long as it is an embodiment in which they can be contacted at 200 ° C. or lower as described above, and for example, one side is added to the other side. By making it easy to contact, In particular, it is preferable to contact these in the granulation process of carbon black. That is, the silica source can be attached to the surface of the carbon black uniformly and simply by adding the silane and / or the polysiloxane in which all the organic groups are bonded to silicon through oxygen to the unassembled carbon black. The granulation step is preferably wet granulation. Processes are preferred for the process of adding silane and / or polysiloxanes in which all organic groups are bonded to silicon via oxygen in the same amount of granulated water as unassembled carbon black. More preferably, a method of emulsifying and dispersing silane and / or polysiloxane in which all organic groups are bonded to silicon via oxygen in a coarse water with a nonionic surfactant or the like is used. Thus, by performing contact in "in the presence of water", hydrolysis of the organic group couple | bonded with the silicon | silicone through oxygen is promoted in the drying process which is the next process, and many silanol groups are produced | generated.

After granulation, the drying process is carried out, but the residual moisture in the drying step is preferably 5% by weight or less. The drying process can be performed using an apparatus such as a dryer in the presence of moisture. At this time, it is considered that a part of the organic group bonded to silicon via oxygen is hydrolyzed to generate silanol groups.

Although the surface-treated carbon black obtained by the method of this invention is not specifically limited, It is preferable that nitrogen specific surface area is 20-300 m <2> / g, and DBP is 50-250 mW / 100g. Since the manufacturing method of this invention does not require the complicated operation like the process with water glass etc., carbon black with a silica can be manufactured simply. In addition, as described below, according to the production method of the present invention, since substantially the entire amount of the silica component can be uniformly present on the surface of the carbon black as a fine region, the carbon with silica exhibiting a large effect in a small amount. You can get black. In addition, quality control is also easy. Further, according to the present invention, almost all the amount of the silica component, i.e., 80 wt% or more and 90 wt% or more can be attached to the carbon black, so the production rate is very good.

As mentioned above, the carbon black of this invention can be obtained by the manufacturing method of this invention demonstrated. Namely, the carbon black having silica attached to the surface thereof, wherein at least 80% by weight of the attached silica has a thickness of 0.1 to 20 nm and a width of 1 to 40 nm. The attached silica may be 0.1-15 nm in thickness, 1-30 nm in width, and also 1-20 nm. And 90 weight% or more of the attached silica can also be made into the said range. That is, the carbon black of the present invention can attach the silica component in a fine and uniform state and can exhibit high characteristics. Here, the thickness of silica means the direction perpendicular to the carbon black surface, and the width means the direction perpendicular to the thickness direction. The size of the silica component can be confirmed by transmission electron micrographs. Specifically, the shape and the thickness and the width can be measured by confirming the shape by a transmission electron micrograph or, if necessary, by the transmission type electron micrograph with respect to the part identified as a silica component by means, such as EDX.

And almost all of the silica component can be present on the surface of the carbon black. In addition, in the carbon black of this invention, it processes with the specific silicon compound. That is, silanes and / or siloxanes in which all organic groups are bonded to silicon via oxygen. Since the surface treatment is carried out using such a compound, a large amount of OH groups are easily formed on the surface of the carbon black which has been surface-treated, and thus, it can be made excellent in adhesion with the vehicle when blending with rubber or the like.

The compounding quantity to rubber is 10-200 weight part normally with respect to 100 weight part of rubber components, Preferably it is 20-150 weight part.

The rubber component used in the rubber composition of the present invention is not particularly limited but is preferably a crosslinkable rubber. More preferred are sulfur vulcanizable diene rubbers. Rubber may be used individually or in mixture of 2 or more types.

In the rubber composition of the present invention, in addition to the surface-treated carbon black obtained by the production method of the present invention, ordinary carbon black and silica may be used in combination. However, it is preferable that the compounding quantity does not exceed 5 times of the said surface-treated carbon black.

Moreover, it is preferable that a silane coupling agent is mix | blended with the rubber composition of this invention. As a silane coupling agent, what was conventionally used can be mix | blended arbitrarily, Especially the thing of the at least bifunctional which can react with a silanol group and a rubber type polymer is preferable. Specifically, bis (3-triethoxysilylpropyl)-tetrasulfide, mercapto propyl triethoxysilane, etc. are mentioned. This is because the silanol groups on the surface of the carbon black produced by the present invention react and bond with the alkoxy moiety of the silane coupling agent during mixing kneading, and the sulfide moiety reacts with the rubber polymer in the vulcanization reaction. In this case, the compounding quantity of a silane coupling agent becomes it at least as compared with normal silica compounding by using the surface-treated carbon black obtained by this invention. That is, conventional silica compounding has a problem that the compound cost is expensive because it is usually necessary to add an expensive silane coupling agent to 5 parts by weight to 100 parts by weight of silica, but according to the present invention, the compounding amount of the silane coupling agent Although it depends on the amount of silica deposition with respect to the surface-treated carbon black obtained by this invention, 1-10 weight part is enough. This is because the total amount of silanol groups present on the carbon black surface is smaller than the silanol groups on the surface of normal silica particles, which means that a sufficient amount of silane coupling agent to react. Therefore, the present invention also has the advantage that the compound cost is lower than that of the silica-based compounding.

The rubber composition incorporating the surface treated carbon black obtained in the present invention is suitably provided for tire use such as tire tread, undertread, and side tread, and general rubber members such as dustproof rubber and belt.

Hereinafter, an Example demonstrates this invention.

EXAMPLES 1-7

Preparation of Surface Treated Carbon Black

As carbon black, 1000 g of unassembled product of "N220" ("DIABLACK-I": Mitsubishi Chemical Co., Ltd. product) is put into a laboratory granulation apparatus. Predetermined amount of oligomer (trade name: "MKC silicate MS51" Mitsubishi Chemical Co., Ltd.), which is a low-condensation product of tetramethoxysilane, as silane and / or polysiloxane in which all organic groups are bonded to silicon via oxygen (described in Table 1) ) Is emulsified with a nonionic surfactant (trade name: "Emulgen 920" Gao Corporation) and added to the carbon black together with water. Close the lid of the lab assembly and stir at 60 ° C. for 1 minute at high speed. The granulated product thus obtained is dried with a drier to obtain surface treated carbon black of Examples 1 to 6.

Subsequently, as a silane and / or polysiloxane in which all organic groups are bonded to silicon via oxygen, hydrolysis-condensates obtained by hydrolyzing "MKC silicate MS51" by adding 0.57 molar amount of water to the alkoxy group of MS51 in ethanol. : The surface-treated carbon black of Example 7 is obtained by performing the same operation as mentioned above using "MKC silicate MS51SG1" Mitsubishi Chemical Corporation.

[Comparative Examples 1-3]

On the other hand, the same operation as in Example was carried out except that silane and / or polysiloxane in which all organic groups were bonded to silicon via oxygen was not added, and in which silica of Comparative Example 1 was not impregnated, Carbon black is obtained.

In addition, the comparative example 2 is a silica sweet rice (brand name: "Nipsil AQ" Nippon Silica Kogyo Co., Ltd.), and the comparative example 3 is a mechanical mixture (blend) of carbon black and silica (Nipsil AQ).

Measurement of Silica Content and Colloidal Properties of Surface-treated Carbon Blacks

Surface-treated carbon black is carbonized at 750 degreeC based on the carbon powder measuring method of JISK6221, and carbon content is calculated | required. The amount of the carbon black obtained by subtracting the carbon black carbon content of Comparative Example 8, in which silica is not impregnated, is regarded as the silica content. The results are shown in Table 1 along with other colloidal characteristic values. And the measuring method of the colloidal characteristic value is as follows.

Nitrogen Specific Surface Area: ASTM D3037

CTAB Specific Surface Area: ASTM D3765

Iodine adsorption amount: JIS K6221 "Test method of carbon black for rubber"

DBP Oil Absorption: JIS K6221 "Test Method of Rubber Carbon Black"

Preparation of Surface-treated Carbon Black-containing Rubber Compositions and Measurement of Rubber Properties

Each component shown in Table 2 is knead | mixed and knead | mixed with a Banbury mixer and an open roll mixer according to a conventional method, and a rubber composition is manufactured ("SBR1502" of Table 2 is styrene butadiene rubber "1502" made by Nippon Kosei Kogyo Co., Ltd. (styrene). Amount 23.5% by weight). These rubber compositions are press vulcanized at 160 ° C. to prepare vulcanized rubber test pieces. Various tests are carried out by the following test methods to measure their properties.

(1) E ^* , tanδ: The dynamic viscoelastic properties E ^* and tanδ are measured under the following conditions using "DVE Leo Spectrum" manufactured by Leorod Corporation.

E ^* : static torsion 10%, dynamic torsion (amplitude) 0.3%, frequency 20 Hz, measurement temperature -10 ℃

tanδ: static torsion 10%, dynamic torsion (amplitude) 4%, frequency 20 Hz, 2 levels of measurement temperature 0 ℃ and 60 ℃

(2) Abrasion resistance: Measured under the following conditions using a lanbon abrasion tester.

Test piece: thickness 10 mm, outer diameter 44 mm, test load 4 kg, slip rate of grindstone and test piece 45%, measuring temperature 25 ℃

(3) Dispersion degree of reinforcing particles in rubber (D%): Measurement method of dispersion degree of carbon black Based on ASTM D2663-B method (agglomeration counting method). That is, the vulcanized rubber was sliced into a thin film with a sledge-type microtome (manufactured by Leitz), and the total cross-sectional area occupied by agglomerates of 5 μm or more of reinforcing particles (carbon black or silica) in the compound was measured using an optical microscope, and the mixture was added to the compound. From the total cross-sectional area (calculated value) of the reinforcing particles, the percentage of reinforcing particles dispersed at 5 μm or less is determined to be the degree of dispersion (D%).

Table 3 shows the obtained results of (1) to (3).

Preparation and Characteristic of Silica Impregnated Carbon Black  Yes Example Comparative Example  Conduct number One 2 3 4 5 6 7 One 2 3  Reinforcement Particle Type Si-attached CB Si-attached CB Si-attached CB Si-attached CB Si-attached CB Si-attached CB Si-attached CB CB Silica CB / Silica Blend  N220 (g) * 1) MS51 (g) * 2) MS51SGI (g) * 3) 10004.8- 10009.6- 100019.2- 100038.4- 100096- 1000192- 1000-125 100000 --- --- MS51 addition amount (large CB weight part) MS51SGI addition amount (large CB weight part) SiO ₂ content (%): Theoretical value * 4) 0.48-0.25 0.96-0.5 1.92-1 3.84-2 9.6-5 19.2-10 -12.52 000 --100 --5  CB / Silica * 5) Blend Ratio - - - - - - - 100/0 0/100 95/5 Carbon content (%) Assumption of SiO ₂ * 6) (%) 0.290.21 0.550.47 1.11.02 2.031.95 4.724.64 8.748.66 2.051.97 0.080 95.995.9 4.874.79  Nitrogen specific surface area (㎡ / g) CTAB specific surface area (㎡ / g) Iodine adsorption (mg / g) DBP oil absorption (ml / 100g) 113113108106 109113107105 105112104102 102111101102 9411592103 877485102 10311398102 115111110106 1921980.1169 119115105109 * 1) Unassembled product of DIABLACK-I (manufactured by Mitsubishi Chemical Corporation) * 2) MKC silicate MS51 (manufactured by Mitsubishi Chemical Corporation) * 3) MKC silicate MS51SG1 (manufactured by Mitsubishi Chemical Corporation) * 4) Theory in MS51 or MS51SG1 Value calculated by weight% of SiO ₂ in CB per weight * 5) Value calculated by Nipsil AQ (manufactured by Nippon Silica Kogyo Co., Ltd.) * 6) Carbon content-Carbon content of Comparative Example 1

Preparation of Silica Impregnated Carbon Black-containing Rubber Composition  Yes Example Comparative Example  Conduct number One 2 3-1 3-2 4 5 6 7 1-1 1-2 2 3  [Combination: parts by weight] SBR1502 CB * 2) Silica * 1) Si Impregnated CB Si69 * 3) Zincated Stearic Acid Antioxidant * 4) Sulfur Vulcanization Accelerator * 5) Vulcanization Accelerator * 6) 100--5055221.51.21 100--5055221.51.21 100--5055221.51.21 100--5025221.51.21 100--5055221.51.21 100--5055221.51.21 100--5055221.51.21 100--5055221.51.21 100--5005221.51.21 100--5055221.51.21 100-50-55221.51.21 10047.52.5-55221.51.21  * 1) Nipsil AQ (manufactured by Nippon Silica Co., Ltd.) * 2) DIABLACK-I (manufactured by Mitsubishi Chemical Co., Ltd.) * 3) Silane coupling agent: Si69 (manufactured by Degussa) * 4) N- (1,3-dimethylbutyl ) -N'-phenyl-p-phenylenediamine: Santoflex 13 (manufactured by Monsant) * 5) N-tert-butyl-2-benzothiazyl sulfenamide: Santocure NS (manufactured by Monsant) * 6) N, N '-Diphenyl guanidine: knock cer D (Ouchi Shingo Co., Ltd. product)

Rubber properties  Yes Example Comparative Example  Conduct number One 2 3-1 3-2 4 5 6 7 1-1 1-2 2 3 E ^* (-10 ℃) 0.3% * 4) tanδ (0 ℃) 4.0% * 5) tanδ (60 ℃) 4.0% * 6) Abrasion Resistance Index (INDEX) Dispersion of Reinforcement Particle (%) 32.10.3090.1509999.1 32.20.3000.15010198.2 31.50.3000.14610098.7 31.10.3100.15610298.3 30.90.3010.1509998.5 32.40.3030.14910098.7 29.80.2920.1459795.4 30.50.3030.14810099.0 33.50.3110.20010098.3 35.30.2890.1669698.7 31.30.3090.1537891.7 35.00.2900.1619697.9 * 4) Temperature -10 ℃, Static Torsion 10%, Dynamic Torsion (Amplitude) 0.3%, Frequency 20㎐, E ^* Unit MPa * 5) Temperature 0 ℃, Static Torsion 10%, Dynamic Torsion (Amplitude) 4.0%, Frequency 20㎐ * 6) Temperature 60 ℃, Static Torsion 10%, Dynamic Torsion (Amplitude) 4.0%, Frequency 20㎐ * 7) Ranbon Abrasion Test, Sample Thickness 10mm, Load 4kg, Slip Rate 45%, Comparative Example 1- The larger the value of INDEX with 1 as 100, the better (less wear)

In Table 1, the present invention shows that almost all theoretical groups of SiO ₂ adhere to carbon black by surface treatment of carbon black with silica and / or polysiloxane in which all organic groups are bonded to silicon via oxygen. That is, `` Home SiO ₂ minus the theoretical value of SiO ₂ generated from MKC silicate MS51 or MKC silicate MS51SG1 and the carbon content of surface treated carbon black minus the carbon content of untreated carbon black (Comparative Example 1). Quantity ”almost coincided with each other, indicating that the yield was impregnated with good yield.

As Table 2 and Table 3 show, the rubber composition which mix | blended the carbon black (Examples 1-7) which performed the surface treatment by this invention is a rubber composition which mix | blended the normal carbon black which did not surface-treat. Compared with Comparative Example 1-1, only tan δ in the high temperature range (60 ° C.) is reduced while tan δ in the low temperature range (0 ° C.) is kept high. That is, when a rubber composition is used for a tire tread etc., it becomes a tire by which only rotational resistance was reduced, without sacrificing braking property etc. on wet road surfaces. Also, wear resistance is not deteriorated.

The silane coupling is not usually added to the carbon black system, but in Comparative Example 1-2 in which 5 parts by weight of Si69 is added, the tanδ balance between the low temperature region and the high temperature region is considerably close to that of silica. However, since the complex modulus of elasticity (E ^* ) at low temperature and low torsion is high, braking characteristics are particularly poor on low friction coefficient road surfaces and the like. On the other hand, it can be seen that the embodiment is improved because of the low E ^* .

Next, compared with the comparative example 2 which mix | blended normal silica, an Example has the tan (delta) balance of low temperature range and high temperature range (silica level), and it is excellent in abrasion resistance and reinforcement particle dispersibility (normal carbon black level). In other words, it can be seen that the examples have a viscoelastic property of silica level (tan * balance between low temperature range and high temperature range, or E ^* characteristics under low temperature and low torsion), and wear resistance and particle dispersibility of carbon black level.

Comparative Example 3 is a blend of carbon black and silica. As can be seen in comparison with Example 5, where the total silica content in the particles is almost the same, the effect of the present invention cannot be obtained from a simple blend of carbon black and silica, and the carbon black surface-treated by the method of the present invention It can be seen that it should be used only.

[Examples 8 and 9]

As carbon black, Mitsubishi Chemical Co., Ltd. product "N339" (iodine adsorption amount 92 m <2> / g, nitrogen adsorption specific surface area 105 m <2> / g) was used, and 1 weight% and 5 weight% (quantity conversion) of silica were respectively, respectively. Carbon black with silica was obtained by the same method as Example 1 except having used "MS-51" so that it may become. Table 4 shows the conductivity (volume intrinsic resistance) of the obtained carbon black. And the rubber composition is manufactured by mixing and kneading each component shown in Table 5 with a Benbury mixer and an open roll mixer using these carbon black with silica. The physical properties (tanδ) of the obtained rubber composition are shown in Table 4.

The transmission electron micrograph (2,000,000 times) of the silica black carbon black obtained in Example 8 is shown in FIG. 1, and the EDX spectrum of A part and B part in FIG. 1 is shown in FIG. From this, it can be seen that the point A is a silica component, the thickness of the silica component is about 10 nm, and the width is about 20 nm. The same was true for other parts of the carbon black.

[Comparative Examples 4 and 5]

Carbon black was placed in the apparatus used in Example 1, and the liquid diluted with water to make 1% by weight of sodium silicate (reagent) was added so that the silica components would be 1% by weight and 5% by weight (in parts), respectively. Then, 5% sulfuric acid is added to adjust the pH to 9, and the lid of the laboratory granulation apparatus is closed and stirred at 60 ° C for 1 minute at high speed. The granulated material thus obtained is dried with a dryer to obtain carbon black with silica. In the same manner as in Example 8, the conductivity (volume specific resistance) is shown in Table 4. Table 4 shows the physical properties (tan δ) of the rubber composition obtained by producing a rubber composition in the same manner as in Example 8.

Example 8 Example 9 Comparative Example 4 Comparative Example 5 Silica amount (amount) One % 5% One % 5% Rubber property tanδ (0 ° C) 0.467 0.487 0.450 0.436 tanδ (60 ° C) 0.236 0.210 0.223 0.226 Conductivity (Ωcm) 8.71E + 03 9.65E + 03 8.94E + 04 1.05E + 05  (The conductivity (Ωcm) of "N339" is 8.76E + 03, and the conductivity (Ωcm) of silica is 5.75E + 13.)

Preparation of rubber composition (mixing ratio of each component: parts by weight) Component ratio  SBR1502 50 NR (Natural rubber) 50 Carbon black 50 Aroma oil 10 Si69 * 3) 5 Zinc 5 Stearic acid 2 Antioxidant * 4) 2 Sulfur 1.5 Vulcanization accelerator * 5) 1.2 Vulcanization accelerator * 6) 1

In Table 5, * 3), * 4), * 5), and * 6) are the same as in Table 2. In addition, the aroma oil uses the thing of Fuji-Fuji Co., Ltd. product.

As can be seen from Table 4, the compounds 8 and 9 treated with the siloxane compound showed superior rubber properties and conductivity in comparison with Comparative Examples 4 and 5 treated with water glass (sodium silicate).

As described above, since silanol groups can be introduced to the surface of carbon black according to the present invention, reduction of tan δ around 60 ° C of the vulcanized rubber composition, which has been attempted by blending particles having silanol groups such as silica particles, and wear resistance Improvement of physical properties, such as improvement, can be achieved without mix | blending particle | grains, such as a silica.

In addition, complex elastic modulus (E ^* ) and dynamic modulus (E ') in the low temperature range (-10 to 0 ° C) and low torsion (0.1 to 1%) as in the case of blending a silane coupling agent having a sulfur atom are As a result, it is possible to solve the disadvantage that the braking characteristic is lowered.

In addition, according to the surface-treated carbon black of the present invention, it is possible to improve the hard dispersibility and the hard workability, which are defects of silica, to the level of carbon black. Therefore, according to the present invention, reinforcing particles having the advantages of silica and carbon black, that is, reinforcing particles having viscoelastic properties (temperature dependence of tanδ) at the silica level and improving the dispersibility and workability of the silica to the carbon black level, It becomes possible to provide the rubber composition which mix | blends this.

Claims (11)

Carbon black with silica attached to the surface, wherein at least 80% by weight of the attached silica has a thickness of 0.1 to 20 nm and a width of 1 to 40 nm. A method for producing a surface-treated carbon black, comprising contacting carbon black with silane and / or polysiloxane in which all organic groups are bonded to silicon via oxygen at 200 ° C. or lower. The method of claim 2, wherein all the organic groups are bonded to the unassembled carbon black by adding silane and / or polysiloxane in which all organic groups are bonded to silicon via oxygen, or assembling carbon black after addition thereof. A method for producing a surface-treated carbon black in which contact of silane and / or polysiloxane bonded to the carbon black to carbon black is performed in a carbon black granulation step. The method for producing a surface-treated carbon black according to claim 3, wherein the granulation step of carbon black is wet granulation, and the granulation step is carried out after drying until the moisture is 5% by weight or less in a dryer. The method for producing the surface-treated carbon black according to any one of claims 2 to 4, wherein the group bonded to silicon of the silane and / or polysiloxane in which all organic groups are bonded to silicon via oxygen is an alkoxy group. The method for producing surface-treated carbon black according to claim 5, wherein the alkoxy group is a methoxy group. The method for producing the surface-treated carbon black according to any one of claims 2 to 4, wherein the silane and / or polysiloxane in which all organic groups are bonded to silicon via oxygen is a condensate of tetraalkoxysilane. The method for producing surface-treated carbon black according to claim 7, wherein the tetraalkoxysilane is tetramethoxysilane. The surface-treated carbon black according to any one of claims 2 to 4, wherein the amount of silane and / or polysiloxane in which all organic groups are bonded to silicon via oxygen is 0.1 to 50 parts by weight based on 100 parts by weight of carbon black. Manufacturing method. The rubber composition obtained by mix | blending the carbon black obtained by the manufacturing method in any one of Claims 2-4 with a rubber component. The rubber composition formed by mix | blending the carbon black of Claim 1 with a rubber component.