KR20220111438A - Rubber composition for tire and tire comprising the same - Google Patents

Abstract

Provided are a tire rubber composition having improved vulcanization efficiency and mechanical properties and a tire comprising the same. The tire rubber composition according to the present invention comprises: 100 parts by weight of raw rubber; 30 to 100 parts by weight of a reinforcing filler; and 1 to 8 parts by weight of a vulcanization accelerator based on 100 parts by weight of the raw rubber, wherein the vulcanization accelerator includes a first inorganic vulcanization accelerator having a surface area, Brunauer Emmett Teller (BET) of 10 to 30 m^2/g.

Description

Tire rubber composition and tire comprising same

The present invention relates to a tire rubber composition and a tire comprising the same, and more particularly, by using, as a vulcanization accelerator, eco-friendly zinc oxide, which is manufactured by wet using zinc dust and has a large specific surface area of particles due to increased irregularities on the surface. , relates to a tire rubber composition that improves the vulcanization properties and mechanical properties of tire rubber to the same or higher level even with a small content compared to the conventional vulcanization accelerator, and a tire comprising the same.

Zinc oxide is a representative vulcanization accelerator, and it is known that it activates the vulcanization accelerator to promote the accelerating reaction, but does not directly affect the crosslinking between sulfur and rubber chains. However, since it affects the degree of crosslinking through an accelerated reaction, ZnO has become essential for crosslinking rubber using sulfur.

Currently, while interest in the environment and health is increasing and legal restrictions (EU ELV (End of Life Vehicle) Directive) are being strengthened, zinc oxide (ZnO) and compounds containing zinc are becoming a problem, and accordingly, rubber products also requires the use of a minimum amount of zinc oxide (ZnO).

By melt-kneading zinc oxide, stearic acid, and an accelerator in various ways to reduce the amount of zinc oxide (ZnO) used, the interaction between each other is improved, and the method of input to rubber and the carrier There was a method of manufacturing and using zinc loaded clay using the use of zinc oxide, and a method of reducing the amount of use of zinc oxide with a large specific surface area.

In particular, the conventional zinc oxide is manufactured using zinc or a zinc material as a precursor, so there is a problem in that the unit cost is relatively high. Zinc oxide prepared by using the zinc material as a precursor has a large specific surface area and is expected to greatly improve the mechanical properties of the rubber compound, but it has a limited effect only in the rubber compound with a high application content, and the rubber compound with a small content does not show a greater effect than expected for the price. This is because the agglomeration phenomenon is further increased at a small content due to the high specific surface area of the zinc oxide.

In order to solve the above problems, research has been continuously conducted on improving mechanical properties in a small amount of rubber compound and at the same time producing a tire rubber composition that is manufactured at a lower unit cost than a tire rubber composition using zinc oxide. have.

An object of the present invention is to provide an eco-friendly tire rubber composition by reducing the content of zinc oxide in a tire rubber composition by using zinc oxide, which is wet-made using zinc dust and has a large specific surface area, as a vulcanization accelerator.

Another object of the present invention is to increase the crosslinking active point and the degree of crosslinking by using zinc oxide with a large specific surface area as a vulcanization accelerator, which is manufactured wet using zinc dust, and thus has improved mechanical properties even when a small content is added. to provide a composition.

Another object of the present invention is to use zinc oxide, which is wet-made using zinc dust and has a large specific surface area, as a vulcanization accelerator, compared to conventional zinc oxide using a zinc material or zinc ingot as a precursor of zinc oxide. , to provide a tire rubber composition exhibiting a cost reduction effect and low fuel efficiency characteristics.

Another object of the present invention is to provide a tire comprising the tire rubber composition.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention not mentioned may be understood by the following description, and will be more clearly understood by the examples of the present invention. Moreover, it will be readily apparent that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

An embodiment of the present invention for achieving the above object includes 100 parts by weight of raw rubber, 30 to 100 parts by weight of a reinforcing filler and 1 to 8 parts by weight of a vulcanization accelerator with respect to 100 parts by weight of the raw rubber, wherein the vulcanization accelerator corresponds to the tire rubber composition including the first inorganic vulcanization accelerator having a surface area, Brunauer Emmett Teller (BET) of 10 to 30 m ² /g.

Another embodiment of the present invention for achieving the above object includes 100 parts by weight of raw rubber, 30 to 100 parts by weight of a reinforcing filler and 1 to 8 parts by weight of a vulcanization accelerator with respect to 100 parts by weight of the raw rubber, wherein the vulcanization accelerator contains a first inorganic vulcanization accelerator having a surface area, Brunauer Emmett Teller (BET) of 10 to 30 m ² /g, wherein the vulcanization accelerator further comprises a second inorganic vulcanization accelerator, and the second inorganic vulcanization accelerator BET (Surface area, Brunauer Emmett Teller) of 3 to 7 m ² /g corresponds to the tire rubber composition.

Another embodiment of the present invention for achieving the above object includes 100 parts by weight of raw rubber, 30 to 100 parts by weight of a reinforcing filler and 1 to 8 parts by weight of a vulcanization accelerator with respect to 100 parts by weight of the raw rubber, wherein the vulcanization The accelerator includes a first inorganic vulcanization accelerator having a surface area, Brunauer Emmett Teller (BET) of 10 to 30 m ² /g, and the vulcanization accelerator further includes a third inorganic vulcanization accelerator, and the third inorganic vulcanization accelerator The BET (Surface area, Brunauer Emmett Teller) of the accelerator corresponds to a tire rubber composition of 60 to 90 m ² /g.

An embodiment of the present invention for achieving the above object includes 100 parts by weight of raw rubber, 30 to 100 parts by weight of a reinforcing filler and 1 to 8 parts by weight of a vulcanization accelerator with respect to 100 parts by weight of the raw rubber, wherein the vulcanization accelerator contains a first inorganic vulcanization accelerator having a surface area, Brunauer Emmett Teller (BET) of 10 to 30 m ² /g, and the vulcanization accelerator further comprises a second inorganic vulcanization accelerator and a third inorganic vulcanization accelerator, The second inorganic vulcanization accelerator, BET (Surface area, Brunauer Emmett Teller) is 3 to 7 m ² /g, The third inorganic vulcanization accelerator, BET (Surface area, Brunauer Emmett Teller) is 60 to 90 m ² /g It corresponds to the tire rubber composition.

Another embodiment of the present invention for achieving the above object corresponds to a tire including the tire rubber composition.

According to the present invention, it is possible to provide an eco-friendly tire rubber composition by reducing the content of zinc oxide in the tire rubber composition by using zinc oxide, which is wet-made using zinc dust and has a large specific surface area, as a vulcanization accelerator.

According to the present invention, a tire rubber composition with improved mechanical properties even when a small amount is added by increasing the crosslinking active point and degree of crosslinking by using zinc oxide with a large specific surface area as a vulcanization accelerator and manufactured in a wet manner using zinc dust can provide

According to the present invention, by using zinc oxide, which is manufactured wet using zinc dust and has a large specific surface area, as a vulcanization accelerator, the cost is reduced compared to conventional zinc oxide using zinc material or zinc ingot as a precursor of zinc oxide. It is possible to provide a tire rubber composition exhibiting an effect and low fuel efficiency characteristics.

According to the present invention, it is possible to provide a tire comprising the tire rubber composition.

In addition to the above-described effects, the specific effects of the present invention will be described together while explaining the specific contents for carrying out the invention below.

Hereinafter, each configuration of the present invention will be described in more detail so that those of ordinary skill in the art to which the present invention pertains can easily carry out, but this is only an example, and the scope of the present invention is defined by the following contents Not limited.

An embodiment of the present invention includes 100 parts by weight of raw rubber, 30 to 100 parts by weight of a reinforcing filler and 1 to 8 parts by weight of a vulcanization accelerator with respect to 100 parts by weight of the raw rubber, wherein the vulcanization accelerator is, BET (Surface area) , Brunauer Emmett Teller) of 10 to 30 m ² /g corresponds to the tire rubber composition comprising the first inorganic vulcanization accelerator.

Hereinafter, the configuration of the present invention will be described in more detail.

The raw rubber according to the present invention may correspond to one selected from the group consisting of natural rubber, synthetic rubber, and combinations thereof.

The natural rubber may be a general natural rubber or a modified natural rubber. As the general natural rubber, any known natural rubber may be used, and the country of origin is not limited. The natural rubber mainly includes cis-1,4-polyisoprene, but may also include trans-1,4-polyisoprene according to required properties. Therefore, in the natural rubber, in addition to natural rubber containing cis-1,4-polyisoprene as a main component, natural rubber containing trans-1,4-isoprene as a main component, such as Valata, which is a type of rubber of the Sapotaceae family from South America, as a main component It may also include rubber.

The modified natural rubber means that the general natural rubber is modified or refined. For example, the modified natural rubber may include epoxidized natural rubber (ENR), deproteinized natural rubber (DPNR), hydrogenated natural rubber, and the like.

The synthetic rubber may be any one selected from the group consisting of styrene-butadiene rubber (SBR), modified styrene-butadiene rubber, butadiene rubber (BR), modified butadiene rubber (Modified-BR), and combinations thereof.

The reinforcing filler according to the present invention may correspond to one selected from the group consisting of carbon black and silica, and combinations thereof.

The reinforcing filler according to the present invention may include 30 to 100 parts by weight based on 100 parts by weight of the raw rubber. When the content of the reinforcing filler is less than the numerical range, there may be a problem of a decrease in stiffness, and when the content of the reinforcing filler is exceeded, there may be a problem in that the initial grip expression performance is lowered.

The vulcanization accelerator according to the present invention may include 1 to 8 parts by weight based on 100 parts by weight of the raw rubber. If the content of the vulcanization accelerator is less than the numerical range, there may be a problem in that the vulcanization efficiency is lowered. The surface may be contaminated.

The vulcanization accelerator according to the present invention may include a first inorganic vulcanization accelerator having a BET (Surface area, Brunauer Emmett Teller) of 10 to 30 m ² /g.

The first inorganic vulcanization accelerator may be zinc oxide (ZnO) prepared by wet oxidation of zinc dust.

Specifically, the method for producing the first inorganic vulcanization accelerator includes the steps of adding zinc dust to a strong acid to provide a first mixture, adding zinc powder to the first mixture to form a second mixture, the second mixture It may include a step of increasing the pH of and drying the second mixture having the increased pH. The heat treatment of the second mixture may be performed at 400 to 600°C.

The average particle size of the zinc powder may correspond to 300 to 600 nm (nanometers), preferably 300 to 350 nm (nanometers).

The first inorganic vulcanization accelerator is manufactured in a wet manner using zinc dust, and thus is environmentally friendly as the content of heavy metals is significantly lower than that of zinc oxide manufactured in a dry method.

In addition, the first inorganic-based vulcanization accelerator may correspond to particles having an increased surface asperity by being prepared in a wet manner. As a result, the specific surface area of the particles is increased, and thus the vulcanization efficiency can be increased.

Additionally, when the first inorganic vulcanization accelerator is used in a small amount, the crosslinking active point and the degree of crosslinking may be increased. Accordingly, the elongation of the tire rubber including the first inorganic vulcanization accelerator may be increased to increase the tensile strength of the tire rubber.

Specifically, looking at the mechanism _by which the degree of crosslinking is increased, the increase in the concentration of zinc ions (Zn ²⁺ ) in the rubber compound is an overall speed can be increased. Specifically, zinc ions (Zn ²⁺ ) may form a chelate compound with rubber-sulfur-accelerator (Rubber-S _x -Acc) in which rubber, sulfur, and an accelerator are combined. Accordingly, the chelate compound is more reactive than the accelerator that did not form the chelate compound during the initial reaction, thereby accelerating the crosslinking action. In addition, during the crosslinking reaction, zinc ions may form a polar bond with a silanol group on the silica surface to act as a reaction initiator.

The chelate compound has high reactivity, and may be more easily broken than the bond between sulfur and sulfur (S _x -S _y ) to increase the degree of crosslinking. The chelate compound refers to a complex ion formed by coordinating one ligand with a metal ion at two or more sites. The ligand corresponds to the rubber-sulfur-promoter, and the metal ion corresponds to the zinc ion.

The average particle size of the zinc dust may correspond to 20 to 50 nm (nanometers), preferably 25 to 45 nm (nanometers).

The zinc dust may include 99 wt% or more of zinc based on the total weight of the zinc dust. Preferably, the zinc content may correspond to 99 to 99.9 wt% based on the total weight of the zinc dust.

In summary, the first inorganic vulcanization accelerator according to the present invention is prepared in a wet manner using zinc dust (secondary dust) as its precursor, so that the surface area of the first inorganic vulcanization accelerator particles increases by increasing the specific surface area. can As the specific surface area of the particles of the first inorganic vulcanization accelerator increases, the vulcanization efficiency increases and the content of added zinc oxide is reduced, thereby manufacturing an eco-friendly tire rubber composition.

In addition, the first inorganic vulcanization accelerator according to the present invention may exhibit mechanical properties and vulcanization properties equivalent to or higher than those of conventional zinc oxide using zinc material or zinc ingot as a precursor of zinc oxide.

The vulcanization accelerator according to another embodiment of the present invention may further include a second inorganic vulcanization accelerator, and the surface area, Brunauer Emmett Teller (BET) of the second inorganic vulcanization accelerator may correspond to 3 to 7 m ² /g. can

The second inorganic vulcanization accelerator may be prepared by melting metallic zinc at a temperature of about 1000° C. using a crucible, and then oxidizing the molten metallic zinc through contact with air. Accordingly, the second inorganic vulcanization accelerator may correspond to zinc oxide (ZnO).

The precursor of the second inorganic vulcanization accelerator may be a zinc ingot (Zn ingot). The zinc ingot may include 90 to 99.9 wt% of zinc, preferably 99 to 99.8 wt%, based on the total weight of the zinc ingot. The zinc ingot may be produced through an ultra-high purification process such as crystallization or sublimation.

The vulcanization accelerator according to another embodiment of the present invention may further include a third inorganic vulcanization accelerator. The third inorganic vulcanization accelerator BET (Surface area, Brunauer Emmett Teller) may correspond to 60 to 90 m ² /g.

The precursor of the third inorganic vulcanization accelerator is a zinc material, and the zinc material may include 80 to 90 wt% of zinc based on the total weight of the zinc material.

Specifically, the third inorganic vulcanization accelerator may correspond to active zinc oxide (Active ZnO). The manufacturing method of the active zinc oxide (Active ZnO) comprises the steps of adding the zinc material to a strong acid solution to form a third mixture, adding a basic solution to the third mixture to increase the pH of the third mixture And after heat-treating the third mixture having an increased pH at 400 to 600° C., it may include drying it.

The tire rubber composition according to another embodiment of the present invention may further include 5 to 10 parts by weight of oil based on 100 parts by weight of the raw rubber. When the content of the oil is less than the numerical range, there may be a slight difference in performance, and if it exceeds the numerical range, there may be a problem in that the rigidity is lowered.

The oil is added to the rubber composition to facilitate processing by imparting plasticity to the rubber or to reduce the hardness of the vulcanized rubber, and refers to processing oils used during rubber compounding or rubber manufacturing. As the oil, any one selected from the group consisting of petroleum oils, vegetable oils and combinations thereof may be used, but the technical spirit of the present invention is not limited thereto.

The tire rubber composition according to the present invention may further include a coupling agent to improve dispersibility of the reinforcing filler. As the coupling agent, a sulfide-based silane compound, a mercapto-based silane compound, a vinyl-based silane compound, an amino-based silane compound, a glycidoxy-based silane compound, a nitro-based silane compound, a chloro-based silane compound, a methacrylic silane compound, and combinations thereof Any one selected from the group consisting of may be used.

The tire rubber composition according to the present invention may further include additives. The additive may optionally correspond to various additives such as a vulcanizing agent and an anti-aging agent. Any of the above various additives may be used as long as they are commonly used in the field to which the present invention pertains, and their content is not particularly limited as it depends on a compounding ratio used in a typical tire rubber composition.

The vulcanizing agent may be a sulfur-based vulcanizing agent, an organic peroxide, a resin vulcanizing agent, a metal oxide such as magnesium oxide.

The antioxidant is an additive used to stop the chain reaction in which the tire is automatically oxidized by oxygen. As the antioxidant, any one selected from the group consisting of amine-based, phenol-based, quinoline-based, imidazole-based, carbamic acid metal salts, waxes, and combinations thereof may be appropriately selected and used.

Another embodiment of the present invention corresponds to a tire comprising the aforementioned tire rubber composition.

The tire may be a passenger car tire, a racing tire, an airplane tire, an agricultural machine tire, an off-the-road tire, a truck tire, or a bus tire, and preferably a tire for a passenger car. Also, the tire may correspond to a radial tire or a bias tire.

Specifically, the tire rubber composition may be applied to any rubber compound such as a tread of a tire, a reinforcing belt layer, a carcass, a bead part, and a sidewall part.

Hereinafter, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily carry out, but this is only an example, and the scope of the present invention is defined by the following contents Not limited.

[Production Example: Tire Rubber Composition]

Tire rubber compositions according to Examples and Comparative Examples were prepared with the composition shown in Table 1 below. The rubber composition was prepared by a conventional method for preparing a rubber composition.

[Experimental Example: Measurement of Physical Properties of Rubber Specimens]

The physical properties of the rubber specimens prepared in Examples and Comparative Examples were measured, and the results are shown in Table 2 below as an index. Each measurement method is as follows.

1) Mooney viscosity (ML1+4 (160℃))

Using a Mooney MV2000 (Alpha Technology) instrument, it was measured according to ASTM standard D1646 at a large rotor, preheating 1 minute, rotor operating time 4 minutes, and a temperature of 160°C. Mooney viscosity is a value indicating the viscosity of unvulcanized rubber. The higher the Mooney viscosity value, the greater the viscosity of the rubber, and thus processability may be disadvantageous. The lower the Mooney viscosity value, the better the processability.

2) MDR (Moving Die Rheometer; t90, Tmin/Tmax)

The curing time t90 (min) of the rubber composition was measured at 160° C. using a rheometer. The larger t90(min), the longer the vulcanization time of the rubber, and the smaller t90(min), the shorter the vulcanization time.

On the other hand, it is a device that measures the processability and vulcanization characteristics of rubber by measuring the value at which the torque value of the rubber increases through the vulcanization reaction over time by applying a temperature to the unvulcanized rubber specimen. The value at the highest torque value is Tmax, The lowest value was set as Tmin.

3) S-S (M300)

SS is an evaluation index for measuring strain-stress, and M300 is to measure the force applied when a rubber specimen is deformed by 300%. Typically, the unit corresponds to Kg/cm ² . The higher the size of M300, the more force is required to deform the rubber specimen.

4) tanδ60℃

For viscoelasticity, tanδ at 60°C was measured under 10Hz frequency at 0.5% strain using an ARES meter. tanδ60°C is a measure of the rolling resistance at 60°C, and the lower the number, the better the low fuel economy characteristics.

Compared with Comparative Examples, Examples 1 to 3 showed equal or lower Mooney viscosity and excellent processability, and showed the same level of vulcanization time (t90), so there was no significant difference in crosslinking reaction, and showed equal or large M300 values. It can be seen that the mechanical strength is excellent and the rotational resistance is low, so that it shows low fuel efficiency.

Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims are also present. It belongs to the scope of the invention.

Claims (12)

100 parts by weight of raw rubber;
30 to 100 parts by weight of a reinforcing filler based on 100 parts by weight of the raw rubber; and
1 to 8 parts by weight of a vulcanization accelerator,
The vulcanization accelerator,
A tire rubber composition comprising a first inorganic vulcanization accelerator having a BET (Surface area, Brunauer Emmett Teller) of 10 to 30 m ² /g. According to claim 1,
The first inorganic vulcanization accelerator is a tire rubber composition prepared by wet oxidation of zinc dust. 3. The method of claim 2,
An average particle size of the zinc dust is 20 to 50 nm. 3. The method of claim 2,
The zinc dust is a tire rubber composition comprising at least 99% by weight of zinc based on the total weight of the zinc dust. According to claim 1,
The vulcanization accelerator,
Further comprising a second inorganic vulcanization accelerator,
The second inorganic vulcanization accelerator BET (Surface area, Brunauer Emmett Teller) is 3 to 7m ² /g tire rubber composition. 6. The method of claim 5,
The second inorganic vulcanization accelerator is zinc oxide (ZnO),
The precursor of the zinc oxide is a zinc ingot (Zn Ingot),
The zinc ingot may include 90 to 99.9 wt% of zinc based on a total weight of the zinc ingot. The method of claim 1,
The vulcanization accelerator,
Further comprising a third inorganic vulcanization accelerator,
The third inorganic vulcanization accelerator BET (Surface area, Brunauer Emmett Teller) is 60 to 90 m ² /g tire rubber composition. 8. The method of claim 7,
The third inorganic vulcanization accelerator is active zinc oxide (Active ZnO),
The precursor of the active zinc oxide is a zinc material,
The zinc material is a tire rubber composition comprising 80 to 90% by weight of zinc based on the total weight of the zinc material. According to claim 1,
The vulcanization accelerator,
Further comprising a second inorganic-based vulcanization accelerator and a third inorganic-based vulcanization accelerator,
The second inorganic vulcanization accelerator is zinc oxide (ZnO) having a BET (Surface area, Brunauer Emmett Teller) of 3 to 7 m ² /g,
The third inorganic vulcanization accelerator is active zinc oxide (Active ZnO) having a BET (Surface area, Brunauer Emmett Teller) of 60 to 90 m ² /g
tire rubber composition. According to claim 1,
The reinforcing filler is one selected from the group consisting of carbon black, silica, and combinations thereof. According to claim 1,
The raw material rubber,
A tire rubber composition, which is one selected from the group consisting of natural rubber, synthetic rubber, and combinations thereof. 12. A tire comprising the tire rubber composition according to any one of claims 1 to 11.