KR20120050818A - Manufacturing method for coated silica on surface of carbon nano tube and application thereof - Google Patents

Abstract

PURPOSE: A manufacturing method of silica coated carbon nanotube and use thereof are provided to enhance wear resistance, rotation resistance property, and braking power on wet road of the tire tread by coating silica on surface of surface modified carbon nanotube. CONSTITUTION: A manufacturing method of silica coated carbon nanotube comprises next steps: washing carbon nanotube(10) which is treated with acid solution in order to accomplish neutral pH; drying to modify surface of the carbon nanotube; putting the modified carbon nanotube into a reactor which includes toluene and benzyl alcohol; irradiating ultrasonic waves after placing the carbon nanotube in a water bath; performing reactions of the carbon nanotube with sodium silicate solution(20); and eliminating moisture after filtering silica coated carbon nanotube. The carbon nanotube comprises 10-100.0 parts by weight of silica coated carbon nanotube based on 100.0 parts by weight of rubber composition.

Description

Manufacturing method for coated silica on surface of carbon nano tube and application etc}

The present invention relates to a method for producing carbon nanotubes coated with silica and its use, and more particularly, to (1) soaking carbon nanotubes in an acidic solution so that the pH of carbon nanotubes treated with strong acid is neutral. Washing with water and drying to modify the surface of the carbon nanotubes; (2) placing the carbon nanotubes having the surface-modified in a reactor containing toluene and benzyl alcohol and placing them in a water bath to irradiate with ultrasonic waves; (3) reacting by adding sodium silicate aqueous solution while stirring the carbon nanotubes after the ultrasonic irradiation is completed in the step (2); (4) After the reaction of step (3) above, the method for producing carbon nanotubes coated on the surface of silica, including filtering the carbon nanotubes coated on the surface of silica and removing moisture, and the method The present invention relates to a tire tread rubber composition comprising carbon nanotubes coated on the surface of silica prepared by the present invention and carbon nanotubes coated on the surface of the silica prepared by this method.

Since rubber is deformed or recovered depending on the force applied, rubber is used in various products such as tires, conveyor belts, and shoes.

For various products made of rubber, various additives are used to suit the characteristics of the product.

Tires should have several different characteristics depending on the parts of the tire. The tread area of the tire that directly touches the ground and directly affects the movement, braking, etc. of the tire has abrasion resistance, rolling resistance that affects fuel economy, and wetness. On the road surface, the characteristics such as braking performance should be excellent.

Among the various additives used in the tread compound of tires, reinforcing fillers used to improve the wear resistance and strength of the tire tread compound have been commonly used, but carbon black has been used since the early 2000s. As fuel economy and wet road braking performance improves as an important issue, the use of silica is gradually increasing.

Since the early 2000s, academia and industry have recognized the potential for nanomaterials and have applied them to various applications.In terms of materials, it is common to apply nanomaterials with a large surface area to enhance the reinforcement of materials. There is this feature.

Among the additives used in tires, the nanomaterial is a representative material in which carbon nanotubes (CNTs) and nanoclays are examined.

The inventors of the present invention, while researching to improve the properties of the tire tread material that can improve the wear resistance, rotational resistance characteristics and wet road braking force, which are properties required for the tire tread without deteriorating the fairness when manufacturing the tire In the present invention, when the carbon nanotubes coated on the surface of the silica-coated carbon nanotubes provided by the method for producing carbon nanotubes coated on the surface of the silica are used in the tire tread rubber composition, the characteristics of the tire treads are improved. It was devised.

Meanwhile, Korean Patent Publication No. 2009-0044637 discloses a prior art related to the tire tread rubber composition to improve the dispersibility by applying 1 to 10 parts by weight of carbon nanotubes, and exhibits physical properties and rotational resistance characteristics equal to or higher. It is characterized by. However, in the prior art, the tread rubber composition is cured, and damping properties are reduced, which is disadvantageous in wet tire road surface characteristics and noise characteristics.

In addition, the Republic of Korea Patent Publication No. 2005-0046851 is characterized in that 5 to 20 parts by weight of nanoclays are simultaneously applied to the rubber composition for tire treads with silica, dispersibility, wear and wet road braking performance by the use of such nanoclays. It is characterized by improving. However, in the prior art, the chemical used to organicize the nanoclay reacts with the vulcanizing component of the rubber material, which becomes vulcanized before the vulcanization process, thereby degrading scorch stability, which is a defect that cannot be used during the actual process.

On the other hand, the above-mentioned prior art is different from each other in the technical characteristics of the present invention in comparison with the configuration of the present invention.

An object of the present invention is to provide a method for producing carbon nanotubes coated with silica to improve wear resistance, rotational resistance and wet road braking force as constituents of the tire tread rubber composition.

Another object of the present invention is to use the carbon nanotubes coated on the surface of the silica-coated carbon nanotubes prepared by the above-described method for producing carbon nanotubes coated on the surface of the silica as a component of a tire tread rubber composition, and to rotate them. It is an object of the present invention to provide a tire tread rubber composition having improved resistance characteristics and wet road braking force.

It is still another object of the present invention to provide a rubber comprising a carbon nanotube coated on a surface of a silica prepared by the above-described method for producing a carbon nanotube coated on a surface of a silica, and a tire including the rubber as a tire tread. To provide.

In order to achieve the above-mentioned object, the present invention (1) the carbon nanotubes are immersed in an acidic solution to wash the pH of the carbon nanotubes treated with the acidic solution to neutral and dried to modify the surface of the carbon nanotubes Making; (2) placing the carbon nanotubes having the surface-modified in a reactor containing toluene and benzyl alcohol and placing them in a water bath to irradiate with ultrasonic waves; (3) reacting by adding sodium silicate aqueous solution while stirring the carbon nanotubes after the ultrasonic irradiation is completed in the step (2); (4) After the reaction of step (3) above, the method for producing carbon nanotubes coated on the surface of silica, including filtering the carbon nanotubes coated on the surface of silica and removing moisture, and the method To provide a tire tread rubber composition comprising a carbon nanotube coated on the surface of the silica prepared by the method and a carbon nanotube coated on the surface of the silica prepared by the above method.

According to the present invention, it is possible to provide a tire tread rubber composition having improved wear resistance, rolling resistance, and wet road braking force, a rubber made of such a rubber composition, and a rubber comprising such a rubber composition.

Figure 1 is a schematic diagram of the production of carbon nanotubes coated on the surface of the silica of the present invention.
2 is a schematic view showing a carbon nanotube (a) treated with an acidic solution and a carbon nanotube (b) coated with a silica of the present invention.

The present invention shows a method of producing carbon nanotubes coated on a surface of silica as a first invention.

The present invention comprises the steps of: (1) immersing the carbon nanotubes in an acidic solution to wash and dry the pH of the carbon nanotubes treated by the acidic solution to be neutral to modify the surface of the carbon nanotubes;

(2) placing the carbon nanotubes having the surface-modified in a reactor containing toluene and benzyl alcohol and placing them in a water bath to irradiate with ultrasonic waves;

(3) reacting by adding sodium silicate aqueous solution while stirring the carbon nanotubes after the ultrasonic irradiation is completed in the step (2);

(4) After the reaction of step (3) above shows a method for producing carbon nanotubes coated on the surface of silica, including filtering the carbon nanotubes coated on the surface of the silica produced and removing moisture.

Hereinafter, a method of manufacturing carbon nanotubes coated on the surface of silica of the present invention will be described in more detail by each step.

(1) surface modification of carbon nanotubes

When manufacturing the carbon nanotubes coated on the surface of silica of the present invention, first, the carbon nanotubes are immersed in an acidic solution, washed with water and dried so that the pH of the carbon nanotubes treated with the acidic solution is neutral, and the surface of the carbon nanotubes is dried. Reform.

When the surface of the carbon nanotubes are modified, the carbon nanotubes are immersed in an acid solution mixed with sulfuric acid and nitric acid at a weight ratio of 5: 1 to 1: 5 for 12 to 36 hours, thereby treating the carbon nanotubes. The surface of the carbon nanotubes can be modified by washing with water and drying so that the pH is 6-8.

In the carbon nanotubes, single wall carbon nanotubes may be used.

In the carbon nanotubes, multi-wall carbon nanotubes may be used.

In the carbon nanotubes, single-walled carbon nanotubes and multi-walled carbon nanotubes may be used.

The single-wall carbon nanotubes in the above may be used having a diameter of 10 ~ 100nm.

In the above, the multi-walled carbon nanotubes may have a diameter of 100 nm or more, preferably 100 to 900 nm.

When the surface of the carbon nanotubes are modified, the carbon nanotubes are immersed in an acid solution mixed with sulfuric acid and nitric acid at a weight ratio of 3: 1 for 24 hours, and the pH of the carbon nanotubes treated with the acid solution is 7 ± 0.5. The surface of the carbon nanotubes can be modified by washing with water and drying to be neutral.

Drying in the above can be performed using a conventional drying method. At this time, as an example of such a drying method, any one or more selected from natural drying, which is left at room temperature to naturally dry, hot air drying to dry with hot air at 40 to 80 ° C, cold air drying to dry with cold air at 0 to 10 ° C, and far-infrared drying In the present invention, such drying is sufficient if the person skilled in the art can be appropriately selected, so the following detailed description of the drying will be omitted.

The treatment of carbon nanotubes by acidic solution by immersing carbon nanotubes in acidic solution minimizes impurities on the surface of carbon nanotubes so that carbon nanotubes and silica precursors react easily to the surface of carbon nanotubes. This is to form silica in the.

(2) Ultrasonic irradiation of surface-modified carbon nanotubes

The surface-modified carbon nanotubes obtained in (1) above were placed in a reactor containing toluene and benzyl alcohol, and then placed in a water bath and irradiated with ultrasonic waves. .

The surface-modified carbon nanotubes were placed in a reactor containing toluene and benzyl alcohol in a weight ratio of 9: 1 to 1: 9, placed in a water bath, and irradiated with ultrasonic waves of 20 kHz to 100 kHz for 1 to 3 hours. have.

The surface-modified carbon nanotubes are placed in a reactor containing toluene and benzyl alcohol in a weight ratio of 1: 1, and then placed in a water bath for 1.5 hours with 70 ± 5 kHz ultrasonic waves.

Ultrasonic irradiation of the carbon nanotubes is carried out to remove impurities that may be contaminated on the surface of the carbon nanotubes during washing and drying in (1).

In addition, the addition of benzyl alcohol to the solvent toluene during the ultrasonic irradiation of carbon nanotubes generates a pi-pi (π-π) bond between the lipophilic carbon nanotubes and the hydrophilic silica precursor added in the next step. It can be carried out to maximize the bonding force with silica on the surface of the carbon nanotubes.

In the benzyl alcohol, benzyl alcohol having a concentration of 1 to 10% may be used, and preferably benzyl alcohol having a concentration of 1 to 10% may be used.

(3) Surface modification and addition of silica precursors to carbon nanotubes irradiated with ultrasonic waves

After the ultrasonic irradiation in the above (2), while stirring the carbon nanotubes, an aqueous solution of sodium silicate, a silica precursor, is added and reacted.

After the ultrasonic irradiation in the above (2), while stirring the carbon nanotube at 500 ~ 1000rpm can be reacted for 12-48 hours by adding 0.1 ~ 0.5L / hr aqueous silica silicate solution.

After the ultrasonic irradiation in the above (2), while stirring the carbon nanotube at 700rpm can be reacted for 24 hours by adding a sodium silicate aqueous solution of 0.3L / hr silica precursor.

After the ultrasonic irradiation is completed in (2), the reaction was performed by adding sodium silicate aqueous solution as a silica precursor while stirring the carbon nanotubes.

As illustrated in FIG. 1, the sodium silicate aqueous solution 20 may be added to the carbon nanotubes while the carbon nanotubes 10 are stirred using the stirrer 30 and the magnetic steerer 31.

(4) Preparation of carbon nanotubes coated on silica surface

After the reaction in (3) above, the carbon nanotubes coated on the surface of the produced silica may be filtered and the moisture may be removed to prepare carbon nanotubes coated on the surface of silica.

Filtration in the above can be carried out using a conventional filtration method, for example, can be carried out using a filter paper, a filtration device. In the present invention, such filtration is sufficient if a person skilled in the art can be appropriately selected, so the details of filtration will be omitted below.

Removal of water in the above can be carried out using a drying method. This drying method may use the drying method mentioned in (1) surface modification of the carbon nanotubes, and thus, details of drying for removing water will be omitted.

The present invention as a second invention includes the carbon nanotubes coated on the surface of the silica prepared by the method for producing carbon nanotubes coated on the surface of the silica mentioned above.

The present invention as a third invention includes the use of the carbon nanotubes coated on the surface of the silica prepared by the method for producing carbon nanotubes coated on the surface of the silica mentioned above.

The present invention is a tire tread rubber comprising carbon nanotubes coated on a surface of silica as a use of carbon nanotubes coated on a surface of the silica prepared by the method for producing carbon nanotubes coated on the surface of silica. The composition is shown.

In the tire tread rubber composition, the tire tread rubber composition comprising the carbon nanotubes coated on the surface of the silica prepared by the above-described method for producing carbon nanotubes coated on the surface of the silica is shown.

In the present invention, in the tire tread rubber composition, 10 to 100 weight of carbon nanotubes coated on the surface of silica prepared by the method for producing carbon nanotubes coated on the surface of silica as described above with respect to 100 parts by weight of the raw material rubber The tire tread rubber composition containing a part is shown.

In the above, the raw material rubber can be used as long as it can be used as the raw material rubber in the conventional tire tread rubber composition.

In the above, the raw material rubber may be used alone.

In the above, the raw material rubber may be used alone.

In the above raw material rubber may be used a mixed rubber mixed with natural rubber and synthetic rubber.

In the above raw material rubber, natural rubber and synthetic rubber may be mixed rubber mixed in a weight ratio of 5 to 95: 5 to 95.

Synthetic rubber is styrene butadiene rubber (SBR), modified styrene butadiene rubber, butadiene rubber (BR), modified butadiene rubber, chlorosulfonated polyethylene rubber, epichlorohydrin rubber, fluorine rubber, silicone rubber, nitrile rubber, hydrogenated Nitrile rubber, nitrile butadiene rubber (NBR), modified nitrile butadiene rubber, chlorinated polyethylene rubber, styrene ethylene butylene styrene (SEBS) rubber, ethylene propylene rubber, ethylene propylene diene (EPDM) rubber, hypalon rubber, chloroprene rubber, Ethylene vinyl acetate rubber, acrylic rubber, hydrin rubber, vinyl benzyl chloride styrene butadiene rubber, bromomethyl styrene butyl rubber, maleic acid styrene butadiene rubber, carboxylic acid styrene butadiene rubber, epoxy isoprene rubber, maleic acid ethylene propylene rubber, carbon Nitric acid butadiene rubber and brominated polyisobutyl isoprene-c o-paramethyl styrene) may be used any one or more selected from the group.

The tire tread rubber composition of the present invention is a carbon nanotube coated on the surface of silica prepared by the method of producing carbon nanotubes coated on the surface of silica as a reinforcing filler, based on 100 parts by weight of raw rubber. 100 parts by weight can be used.

In the present invention, when the carbon nanotube coated on the surface of silica is less than 10 parts by weight based on 100 parts by weight of raw rubber, the role as a reinforcing filler is insignificant, and when it is used in excess of 100 parts by weight, the effect as a reinforcing filler is obvious. There is a possibility that there is no increase in the physical properties, and in the present invention, it is preferable to use 10 to 100 parts by weight of carbon nanotubes coated on the surface of silica with respect to 100 parts by weight of the raw material rubber.

In the present invention, carbon black, silica, calcium carbonate, titanium dioxide, clay, clay, as the second reinforcing filler in addition to the carbon nanotubes coated on the surface of silica Add one or more selected from the group of layered silicate, tungsten, talc, syndiotactic-1,2-polybutadiene (SPB), and plate graphite. It may further include.

The second reinforcing filler may be used 5 to 60 parts by weight based on 100 parts by weight of the raw material rubber.

In the above carbon iodine adsorption 135-145g / kg, DBP adsorption 125-135ml / 100g, it can be used a color of 125-130%.

In the carbon black, iodine adsorption is 140g / kg, DBP adsorption is 130ml / 100g, the coloration of 127% can be used.

In the above, the silica may use a BET surface area of 110 ~ 250 m 2 / g.

In the silica, the surface of the silica treated with silanetriol (silanetriol) can be used.

In the above-described process, the silica treated with the silane triol may be a silane triol treated with 5 to 50% of the silica weight on the surface of silica having a BET surface area of 110 to 250 m 2 / g.

In the above, the layered silicate may be used as the interlayer spacing of 0.1 ~ 10nm.

In the above-described layered silicate, an aspect ratio (l / d) representing a ratio of the plane width l to the thickness d may be 5 or more.

In the above, the layered silicate may have a flat ratio of 5 to 100.

The layered silicate may be a natural layered silicate capable of cation exchange reaction and / or anion exchange reaction.

The layered silicate may be a synthetic layered silicate capable of cation exchange and / or anion exchange reaction.

The layered silicate may be an organic layered silicate organically treated with a material having a cationic group and / or a material having an anionic group.

The layered silicates are montmorillonite, saponite, hectorite, hectorite, rectorite, vermiculite, mica, illite, kaolinite, and kaolinite. Any one selected from the group of sodium montmorillonite (Na-MMT) and claisite 15A can be used.

In the above syndiotactic-1,2-polybutadiene (SPB) has a diameter of 0.01 ~ 0.1㎛, it can be used that the specific surface area of 80 ~ 90m ² / g.

In the above syndiotactic-1,2-polybutadiene (SPB) is a diameter of 1 ~ 10㎛, it can be used a specific surface area of 100 ~ 120m ² / g.

Plate graphite may be used in the above particle size of 0.1 ~ 20㎛.

In the above, the plate graphite may be one having an interlayer spacing of 0.1 to 10 nm.

In the above, the plate graphite may be one having an aspect ratio (l / d) of 5 or more indicating the ratio of the plane width l to the thickness d.

In the above, the plate graphite may have a flat ratio of 5 to 100.

In the above, the plate graphite may have a particle size of 0.1 to 20 μm, an interlayer spacing of 0.1 to 10 nm, and a flat ratio of 5 to 100.

Plate graphite in the above can be used from the following (a) and (b) step.

(A) immersing the graphite in a mixed solution of sulfuric acid and nitric acid in a weight ratio of 1: 9-9:

(B) washing and washing the dried graphite at 700-900 ° C. for 1-5 minutes after immersion.

Immersion in the step (A) is immersed for 10 to 48 hours at 60 ~ 80 ℃, preferably for 10 hours at 70 ℃ to -SO4 ^{2 -} ion of sulfuric acid or -NO ₃ ^- ion of nitric acid between the plate graphite layer To be inserted.

When the tire tread rubber composition of the present invention uses the silica surface-treated with silica and / or silane triol as the reinforcing filler, the coupling agent is used as a silica dispersant to 100 parts by weight of the raw material rubber in order to improve their dispersibility. 0.5-10 parts by weight could be used.

In the above coupling agent, a conventional silane coupling agent may be used, and as an example of such a silane coupling agent, gamma mercapto propyl di-penta-ethoxy tridecaoxy ethoxy silane or Bis trisilyl propyl tetrasulfide (TESPT) can be used.

The coupling agent may be any one or more selected from the group of dimethyl amino ethanol (DMAE) and hexamethyldisilazane (HMDZ).

When the tire tread rubber composition of the present invention uses the silica surface-treated with silica and / or silane triol as the reinforcing filler as described above, a silica dispersion aid is added in an amount of 0.1 to 100 parts by weight based on the raw material rubber. 5 parts by weight may be used.

The silica dispersion aid may be a mixture of hydrocarbon, zinc soap (zn soap) and filler (filler) is mixed.

The silica dispersion aid is a hydrocarbon having 1 to 10 carbon atoms; Zinc 솝; And a mixture of one or more fillers selected from the group consisting of glass fibers, silica, wood powder, chalk, etc., in a weight ratio of 1-8: 1-8: 1-8.

In the silica dispersion aid, the hydrocarbon may be a chain hydrocarbon and / or a cyclic hydrocarbon.

The tire tread rubber composition of the present invention is a reinforcing filler and activator used in conventional tire tread rubber compositions in addition to the above-mentioned raw rubber, carbon nanotubes coated with silica, a second reinforcing filler, a silica dispersing agent, and a silica dispersing aid. Various additives such as anti-aging agents, process oils, vulcanizing agents, and vulcanization accelerators may be appropriately selected and used in predetermined amounts as necessary. However, these are general components used in conventional tire tread rubber compositions, and thus are not essential components of the present invention, and thus the detailed descriptions thereof will be omitted.

The present invention as a fourth invention uses the carbon nanotubes coated on the surface of the silica prepared by the above-described method for producing carbon nanotubes coated on the surface of silica, including carbon nanotubes coated on the surface of silica. Tire tread rubber.

The present invention represents a tire tread rubber composed of the tire tread rubber composition of the third invention mentioned above as a fourth invention.

According to the fifth aspect of the present invention, there is provided a carbon nanotube coated on a surface of silica prepared by the above-described method for preparing carbon nanotubes coated on silica, including carbon nanotubes coated on a surface of silica. The tire tread to which the rubber | gum is a tread is shown.

The present invention represents a tire comprising as a tread a tire tread rubber of the fourth invention mentioned above as a fifth invention.

The tire represents any one selected from a tire for an automobile, a tire for a bus, a tire for a truck, an tire for an aircraft, and a tire for a motorcycle.

In the method for producing the carbon nanotubes coated on the surface of the silica of the present invention and its use, the method for producing the carbon nanotubes coated on the silica by the conditions of various components, contents and the like, and the use thereof, In order to achieve the object of the present invention, it was found that the method for producing carbon nanotubes coated on the surface of silica under the above-mentioned conditions and the use thereof are preferable.

Hereinafter, the content of the present invention will be described by the following examples, comparative examples and test examples. However, these are not limited to the scope of the present invention by these as an embodiment of the present invention.

<Example 1> Preparation of carbon nanotubes coated on the surface of silica

(1) The carbon nanotubes were immersed in an acidic solution mixed with sulfuric acid and nitric acid at a weight ratio of 3: 1 for 24 hours, and washed with a neutral pH of the carbon nanotubes treated with the acidic solution (7 ± 0.5). The surface of the carbon nanotubes was modified by drying with hot air at 50 ° C.

(2) The surface-modified carbon nanotubes were placed in a reactor containing toluene and 50% benzyl alcohol in a weight ratio of 1: 1, placed in a water bath, and irradiated with ultrasonic waves of 70 ± 5 kHz for 1.5 hours. .

(3) After the ultrasonic irradiation was completed in step (2), the sodium silicate aqueous solution was added at 0.3 L / hr while stirring the carbon nanotube at 700 rpm as shown in FIG.

(4) After the reaction in step (3), the reaction product was filtered and water was removed to prepare carbon nanotubes coated on silica surfaces.

Meanwhile, a schematic diagram of the carbon nanotubes 10 coated on the surface of the silica 21 prepared above is shown in FIG. 2 (b), and FIG. 2 (a) shows the carbon nanotubes 10 treated with an acidic solution. It is a schematic diagram shown.

<Example 2>

Styrene butadiene rubber (SBR1721) as a raw material rubber, 45 parts by weight of carbon nanotubes coated with silica prepared in Example 1 on the surface of 100 parts by weight of the raw material rubber, 3 parts by weight of zinc oxide (ZnO), stearic acid (stearic acid) 2 parts by weight, 2 parts by weight of N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine (trade name: Kumanox-13) as an anti-aging agent in a Banbury mixer and blended Got.

1.8 parts by weight of sulfur as a vulcanizing agent, 1.8 parts by weight of N-cyclohexyl-2-benzothiazole-sulfenamide (CZ) as a vulcanizing agent, and N, N-diphenylguanidine as a second vulcanizing accelerator to the rubber compound (DPG) 0.5 parts by weight was added and vulcanized at 160 ° C. for 25 minutes to prepare a rubber.

Table 1 shows the rubber composition of Example 2.

Comparative Example 1

Styrene butadiene rubber (SBR1721) as a raw material rubber, 70 parts by weight of carbon black, 3 parts by weight of zinc oxide (ZnO), 2 parts by weight of stearic acid, N- as an anti-aging agent based on 100 parts by weight of the raw material rubber 2 parts by weight of (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine (trade name: Kumanox-13) was placed in a Banbury mixer and blended to obtain a rubber compound.

1.8 parts by weight of sulfur as a vulcanizing agent, 1.8 parts by weight of N-cyclohexyl-2-benzothiazole-sulfenamide (CZ) as a vulcanizing agent, and N, N-diphenylguanidine as a second vulcanizing accelerator to the rubber compound (DPG) 0.5 parts by weight was added and vulcanized at 160 ° C. for 25 minutes to prepare a rubber.

In the above, carbon black had a DBP surface area of 114 m 2 / g and a CTAB of 96 m 2 / g.

Table 1 shows the rubber composition of Comparative Example 1.

Comparative Example 2

A rubber was manufactured in the same manner as in Comparative Example 1, except that 70 parts by weight of carbon nanotubes were used instead of 70 parts by weight of carbon black.

In the carbon nanotubes, a multi-walled carbon nanotube having a diameter of 100 nm was used.

Table 1 shows the rubber composition of Comparative Example 2.

&Lt; Comparative Example 3 &

A rubber was manufactured in the same manner as in Comparative Example 1, except that 45 parts by weight of carbon nanotubes were used instead of 70 parts by weight of carbon black.

In the carbon nanotubes, a multi-walled carbon nanotube having a diameter of 100 nm was used.

Table 1 shows the rubber composition of Comparative Example 2.

Composition (unit: parts by weight) of Example 2 and Comparative Examples 1-3 division Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 2 Raw rubber (SBR1721 ^{1 )} ) 100 100 100 100 Carbon Black ^{2 )} 70 - - - Carbon Nanotubes ^{3 )} - 70 45 - Carbon Nanotubes-Silica * - - - 45 Zinc oxide 3 3 3 3 Stearic acid 2 2 2 2 Firefighters ^{4 )} 2 2 2 2 Vulcanizing (sulfur) 1.8 1.8 1.8 1.8 Curing accelerators 1 ^{5 )} 1.8 1.8 1.8 1.8 Curing accelerator 2 ^{6 )} 0.5 0.5 0.5 0.5

1) SBR1721: Styrene 40.5%, Butadiene 59.5%

2) Carbon black: Carbon black with DBP surface area of 114㎡ / g and CTAB of 96㎡ / g

3) Carbon nanotubes: Multi-walled carbon nanotubes with a diameter of 100nm

4) Antioxidant: N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine (Kumanox-13)

5) Vulcanization accelerator 1: N-cyclohexyl-2-benzothiazole-sulfenamide (CZ)

6) Vulcanization accelerator 2: N, N-diphenylguanidine (DPG)

* Carbon Nanotubes-Silica: Carbon nanotubes coated on the surface of silica prepared in Example 1

&Lt; Test Example 1 >

For each rubber specimen prepared in Example 2 and Comparative Examples 1-3, hardness, braking force (0 ° C tanδ), rolling resistance property (70 ° C tanδ), and abrasion property (DIN) according to ASTM-related regulations Abrasion test) and the physical properties are measured and the results are shown in Table 2 below.

Physical Properties of Example 2 and Comparative Examples 1-3 division Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 2 Hardness 100 158 101 102 0 ℃ tanδ 0.86 0.62 0.80 0.92 70 ℃ tanδ 0.18 0.19 0.12 0.09 DIN wear (g) 0.152 0.132 0.124 0.111

* The hardness is expressed in exponential, when the rubber specimen hardness value of Comparative Example 1 is 100, the higher the conversion value, the higher the hardness.

* 0 ° C tanδ is measured by GABO tester and 11Hz. Used as an index of wet road braking performance, the higher the value, the better the wet road braking performance.

* 70 ℃ tanδ is measured by GABO tester and is measured by 11Hz. Used as an index of rotational resistance performance, the lower the value, the better the rotational resistance performance.

* DIN wear test evaluates tire wear prediction. The lower the value, the better the wear characteristics.

As can be seen from the results of Table 2, when carbon nanotubes (Comparative Examples 2 and 3) are used as the components to be added to rubber, the hardness is increased and the wear characteristics are higher than those of carbon black (Comparative Examples 1). However, wet road surface braking performance (0 ° C tanδ) decreases. However, in the case of applying the carbon nanotubes coated on the surface of the silica of the present invention (Example 2), it can be seen that wet road surface braking performance (0 ° C. tanδ), rotational resistance performance (70 ° C. tanδ) and wear characteristics were all improved. there was.

<Example 3>

60 parts by weight of carbon nanotubes coated on the surface of silica prepared in Example 1, and 15 parts by weight of silica treated with silane triol based on 100 parts by weight of natural rubber as raw material rubber 3 parts by weight of bis trisilyl propyl tetrasulfide (TESPT) as a coupling agent, and a hydrocarbon, zinc Zn soap, and filler as a silica dispersion aid in a weight ratio of 1: 1: 1. 1.5 parts by weight of the mixture, 3 parts by weight of zinc oxide (ZnO), 2 parts by weight of stearic acid, N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine as an antioxidant (Brand name: Kumanox-13) 2 weight part was put into Banbury mixer and mix | blended, and the rubber compound was obtained.

To the rubber compound, 1.8 parts by weight of sulfur as a vulcanizing agent and 1.8 parts by weight of N-cyclohexyl-2-benzothiazole-sulfenamide (CZ) as a vulcanization accelerator were added and vulcanized at 160 ° C. for 25 minutes to prepare a rubber.

As described above, the silica treated with the silane triol used a silane triol treated 30% of the silica weight on the surface of silica having a BET surface area of 120 ± 5 m 2 / g.

Among the silica dispersion aid components, the high carbon used a chain-shaped hydrocarbon having 10 carbon atoms, and the filler used glass fiber.

<Example 4>

A rubber was manufactured in the same manner as in Example 3, except that 100 parts by weight of the raw material rubber consisting of 50 parts by weight of natural rubber and 50 parts by weight of styrene butadiene rubber (SBR1721) was used as the raw material rubber.

<Example 5>

50 parts by weight of natural rubber, 50 parts by weight of styrene butadiene rubber (SBR1721), based on 100 parts by weight of the raw material rubber, the silica nanoparticles coated on the surface of the carbon nanotube 60 parts by weight, syndiotactic-1,2 15 parts by weight of polybutadiene (SPB), 3.5 parts by weight of gamma mercapto propyl di-penta-ethoxy tridecaoxy ethoxy silane as a silane coupling agent, 1.5 parts by weight of a mixture of carbon, zinc soap and filler in a weight ratio of 1: 1: 1, 3 parts by weight of zinc oxide (ZnO), 2 parts by weight of stearic acid, As an antioxidant, 2 parts by weight of N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine (trade name: Kumanox-13) was placed in a Banbury mixer and blended to obtain a rubber compound.

1.8 parts by weight of sulfur as a vulcanizing agent and 1.8 parts by weight of N-cyclohexyl-2-benzothiazole-sulfenamide (CZ) were added to the rubber compound as a vulcanizing agent and vulcanized at 160 ° C. for 25 minutes to prepare a rubber. It was.

In the above syndiotactic-1,2-polybutadiene (SPB) was used a diameter of 1 ~ 10㎛, a specific surface area of 100 ~ 120m ² / g.

Among the silica dispersion aid components, the high-carbon used a chain-shaped hydrocarbon having 10 carbon atoms, and the filler used wood flour, which is a wooden particle of 70 ± 2 mesh.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. It will be understood that the present invention can be changed.

A silica tread rubber composition having improved wear resistance, rolling resistance, and wet road braking force as a use for a silica coated carbon nanotube provided by the present invention, and a rubber composed of such a rubber composition and a rubber composition The rubber-containing tires can be provided, which not only contributes to the development of the tire-related industry, but also contributes to the development of the automobile-related industry.

10: carbon nanotube
20: sodium silicate aqueous solution
21: silica
30: stirrer
31: magnetic steerer

Claims (6)

(1) immersing the carbon nanotubes in an acidic solution, washing with water and drying the pH of the carbon nanotubes treated with the acidic solution to be neutral to modify the surface of the carbon nanotubes;
(2) placing the carbon nanotubes having the surface-modified in a reactor containing toluene and benzyl alcohol and placing them in a water bath to irradiate with ultrasonic waves;
(3) reacting by adding sodium silicate aqueous solution while stirring the carbon nanotubes after the ultrasonic irradiation is completed in the step (2);
(4) After the reaction of step (3) is completed, the production of silica coated carbon nanotubes comprising the step of filtering the carbon nanotubes coated on the surface of the silica and removing water Way. The method of claim 1,
(1) The carbon nanotubes were immersed in an acid solution mixed with sulfuric acid and nitric acid at a weight ratio of 5: 1 to 1: 5 for 12 to 36 hours so that the pH of the carbon nanotubes treated with strong acid was 6 to 8 neutral. Washing with water and drying to modify the surface of the carbon nanotubes;
(2) The carbon nanotubes with the surface modified are placed in a reactor containing toluene and benzyl alcohol in a weight ratio of 9: 1 to 1: 9, and then placed in a water bath for 1 to 3 hours using ultrasonic waves of 20 kHz to 100 kHz. Investigating;
(3) adding the sodium silicate aqueous solution at 0.1 to 0.5 L / hr while stirring the carbon nanotubes at 500 to 1000 rpm after the ultrasonic irradiation is completed in the step (2) to react for 1 to 3 hours;
(4) the method of producing carbon nanotubes coated on the surface of silica, characterized in that it comprises the step of filtering the carbon nanotubes coated on the surface of the silica produced on the surface and removing water after the reaction of step (3). . A carbon nanotube coated on a surface of silica prepared by the method of claim 1. In the tire tread rubber composition,
A tire tread rubber composition comprising 10 to 100 parts by weight of carbon nanotubes coated on a surface of silica prepared by the method of claim 1 with respect to 100 parts by weight of raw rubber. A tire tread rubber comprising carbon nanotubes coated on a surface of silica prepared by the method of claim 1. A tire comprising a tread of a tire tread rubber comprising carbon nanotubes coated on a surface of silica prepared by the method of claim 1.

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