KR101791749B1 - Tire cap tread compound with hollow silica - Google Patents

Abstract

The present invention discloses a tire cap tread rubber composition comprising a porous reinforcing filler.
The tire cap tread rubber composition comprising the porous reinforcing filler according to the present invention is characterized in that it comprises a mixture of the porous silica powder and the liquid rubber coated with the organosilane polyol according to Formula 1 and the raw rubber, It is possible to improve the processability and the mixing property with the tread rubber, the energy efficiency is excellent since it is not necessary to apply the heat at a high temperature during the compounding, and the weight of the entire tread rubber can be reduced, thereby improving the fuel efficiency.

Description

Technical Field [0001] The present invention relates to a tire cap tread rubber composition comprising a porous reinforcing filler,

The present invention relates to a tire cap tread rubber composition comprising porous silica, and more particularly, to a tire tread rubber composition which improves workability and processability with tread rubber and does not require high temperature heat during compounding, The present invention relates to a tire cap tread rubber composition which can reduce the weight of the entire rubber and improve the fuel consumption characteristics.

Currently, efforts are being made to develop fuel-efficient tires by reducing the rolling resistance of tires as part of the fuel cost reduction of automobiles. As a result, technologies that use silica as a substitute for carbon black, which has been used in tire tread rubber composition, Is being developed.

However, unlike carbon black, the silica developed for the substitution of carbon black has a polarity of its surface chemistry, so that it is inferior in workability and mixability with a non-polar rubber.

In addition, since these silanol groups of silica are strongly bonded by hydrogen bonding and are not easily dispersed in the compounding process, there is a problem that more shearing force and addition process are required for dispersion of silica in rubber during compounding have.

In order to solve this problem, a silane coupling agent has been developed. This silane coupling agent reacts with the silanol group of the silica to change the polar nature of the silica to nonpolar, and it is easy to mix with the nonpolar rubber It is the role of However, such a silane coupling agent is an expensive substance, and ethanol or the like is generated by reaction with silica in the process, and these are volatilized during the process.

Further, in order to sufficiently react the silica with the silane coupling agent, there is a problem that it is necessary to control the temperature and the time in the mixing process at high temperature.

Therefore, in order to improve the disadvantages of the silane coupling agent, attempts have been made to introduce a dispersant in order to improve the dispersibility and fairness of the silica in the rubber. There is a possibility that another problem of lowering the physical properties of the silica rubber due to the addition of the dispersant may occur.

For example, in Korean Patent Registration No. 10-0840345, porous silica is applied to a tire under-tread to reduce weight and improve heat generation characteristics. However, since it is difficult to disperse the porous silica in the process, the surface- However, there is a problem that it can not be used in a cap tread rubber composition containing a relatively large amount of a reinforcing agent.

In addition, there is a structural problem of hollow porous silica. When hollow silica is used as a filler for a rubber composition, it is easy to reduce the weight. However, because of hollow structure, the strength of silica is weak, There is a problem that various compounds can be introduced into silica during the compounding process and thus the performance is not satisfied.

Therefore, the technical problem to be solved by the present invention is to improve the workability and the mixing property with the tread rubber, and it is not necessary to apply heat at a high temperature in mixing, so that the energy efficiency is excellent and the weight of the entire tread rubber can be reduced, To provide a tire cap tread rubber composition comprising a porous reinforcing filler that improves the properties of the tire.

The present invention relates to a tire comprising a porous reinforcing filler comprising a mixture of a porous silica powder and a liquid rubber coated with an organosilane polyol according to the following Chemical Formula 1 and a raw rubber, A capped tread rubber composition is provided.

≪ Formula 1 >

_{[(O 1/2) 3} -ℓ (HO) ℓ Si] -R 1 -SC (= O) -R 2

(Wherein R ¹ is a C ₁ -C ₁₈ alkylene group or a cyclic hydrocarbon, R ² is a C ₁ -C ₁₈ alkyl group or a cyclic hydrocarbon, and ℓ is an integer of 1≤ℓ≤3)

According to another embodiment of the present invention, the liquid rubber is isoprene or styrene-butadiene rubber, and Mw is 3,000 to 60,000.

According to another embodiment of the present invention, there is provided a tire made of a tire cap tread rubber composition comprising the porous reinforcing filler.

According to the present invention, it is possible to improve the processability and the mixing property with the tread rubber, and it is not necessary to apply heat at a high temperature in mixing, and the energy efficiency is excellent, the weight of the entire tread rubber can be reduced, .

FIG. 1 is a conceptual illustration of a shape in which an organosilane polyol is coated on the surface of silica according to the present invention and a liquid rubber is filled in the silica.

Hereinafter, the present invention will be described in detail.

It is noted that the technical terms used in the present invention are used only to describe specific embodiments and are not intended to limit the present invention. In addition, the technical terms used in the present invention should be construed in a sense generally understood by a person having ordinary skill in the art to which the present invention belongs, unless otherwise defined in the present invention, Should not be construed to mean, or be interpreted in an excessively reduced sense. In addition, when a technical term used in the present invention is an erroneous technical term that does not accurately express the concept of the present invention, it should be understood that technical terms can be understood by those skilled in the art. In addition, the general terms used in the present invention should be interpreted according to a predefined or prior context, and should not be construed as being excessively reduced.

It is also to be understood that the phrase "comprises" or "comprising" or " comprising " It is not necessarily to be construed as being inclusive, and some of the elements or some of the steps may not be included, or may be interpreted to include additional elements or steps.

The tire cap tread rubber composition according to the present invention is characterized by comprising a mixture of a porous silica powder and a liquid rubber coated with an organosilane polyol according to the following Chemical Formula 1 and a raw rubber.

≪ Formula 1 >

_{[(O 1/2) 3} -ℓ (HO) ℓ Si] -R 1 -SC (= O) -R 2

(1 is an integer of ^{1? 3} , R ¹ is a C ₁ -C ₁₈ alkylene group or a cyclic hydrocarbon, and R ² is a C ₁ -C ₁₈ alkyl group or a cyclic hydrocarbon)

May be represented by ℓ in formula (I) as the integer 1≤ℓ≤3 more clearly represented than in particular condensation reaction with an average molecular weight, it expressed with respect to the case where ℓ is 1, 2, 3, (OH ) 3 Si _{-X, (HO) 2 X-} Si-O-SiX (OH) 2 or _{(HO) 2 X-Si-} O 1/2, (HO) 1 X-Si-O or

.

Wherein X is R ¹ -SC (= O) -R ^{2 wherein} R ¹ is a C ₁ -C ₁₈ alkylene group or a cyclic hydrocarbon and R ² is a C ₁ -C ₁₈ alkyl group or a cyclic hydrocarbon.

The liquid rubber is preferably a liquid rubber of isoprene rubber or styrene butadiene rubber having a mass average molecular weight of 3,000 to 60,000. If the average molecular weight is less than 3,000, the unit price will rise too much, It is advantageous to use those having an average molecular weight within the above range because it is difficult to dilute the solvent for adsorption to the surface-modified porous silica.

Here, the solvent may be selected from a wide variety of solvents within a range that can uniformly disperse the liquid rubber. However, the surface of the silica by hydrogen bonding by the hydroxyl group bonded to the organic silane polyol coated on the porous silica It is preferable to avoid the solvent which interferes with penetration into the air or the air, and toluene can be used as an example.

On the other hand, porous silica having a surface coated with an organosilane polyol and hollow spherical porous silica can be obtained by obtaining a hollow spherical porous silica by a Sacrificial core method and coating the surface of the hollow spherical porous silica with an organosilane polyol The Sacrificial core method is a method of manufacturing a hollow sphere by surrounding a spherical polymer with a silica as a core by various coating methods and then dissolving or pyrolyzing the nucleus in a solvent to prepare a hollow sphere having a uniform size. And the coating of the organosilane polyol is not particularly limited as long as it can uniformly coat the surface of hollow spherical porous silica. However, for example, a spray may be used Can be used to coat the organosilane polyol.

After the porous silica coated with the organosilane polyol is immersed in the liquid rubber mixture dispersed in the solvent and stirred, the solvent is removed through the rotary evaporator to obtain the porous silica having the liquid rubber penetrated into the pores. It can be visually understood through FIG.

If the average particle diameter is less than 5 nm, the production cost may increase. If the average particle diameter exceeds 100 탆, the performance of the rubber composition as a reinforcing filler may be deteriorated have.

The porous silica preferably has a BET surface area of 50 to 1,000 m ² / g.

On the other hand, the tire made of the tire cap tread rubber composition can be used as a tire for a passenger car, a tire for a truck, a tire for a bus, a tire for a motorcycle or a tire for an aircraft.

<Production Example>

50 g of the organosilane polyol was spray-coated onto 700 g of hollow spherical porous silica, and the coated porous silica was added to a mixture of 2 kg of toluene and 30 g of liquid isoprene rubber (Kuraray Co. LIR-30, average molecular weight of 28,000) And the solvent was removed through a rotary evaporator. The resulting porous silica coated with the organosilane polyol was washed and dried through 1 kg of toluene to measure its weight, and the amount of the liquid isoprene rubber filled in the porous silica was measured The results are shown in Table 1 below.

<Comparative Production Example>

Porous silica was prepared and weighed in the same manner as in Preparation Example except that the hollow spherical porous silica surface was coated with 50 g of 3-octanoylthiopropyltrethoxysilane. The results are shown in Table 1 below.

division Manufacturing example Comparative Manufacturing Example Total weight 752.8g 750.7 Liquid rubber weight 2.8 g 0.7g

* From the above Table 1, it can be seen that the porous silica according to the production example according to the present invention is effectively filled with the liquid rubber in the inner pores in addition to the surface.

<Examples>

100 parts by weight of raw rubber mixed with 10 parts by weight of natural rubber, 70 parts by weight of styrene butadiene rubber and 20 parts by weight of butyl rubber were prepared, and 75 parts by weight of porous silica prepared by the preparation example, 5 parts by weight of carbon black, 2 parts by weight of stearic acid, 2 parts by weight of wax and 1 part by weight of Polymerized 2,2,4-trimethyl-1,2-dihydroquinoline (TMDQ) were mixed in a Banbury mixer together with the raw rubber to obtain a rubber blend. 2 parts by weight of sulfur as a vulcanizing agent and 2 parts by weight of a vulcanization accelerator (N-cyclohexyl-2-benzothiazol sulfenamide, CZ) were added to the rubber compound and vulcanized at 160 DEG C for 30 minutes to prepare rubber specimens.

&Lt; Comparative Example 1 &

Specimens were prepared in the same manner as in Example except that porous silica according to Comparative Preparation Example was used.

&Lt; Comparative Example 2 &

Specimens were prepared in the same manner as in Example except that 70 parts by weight of silica (Zeosil-115) was used without using porous silica.

<Test Example>

The rubber specimens prepared in the Examples and Comparative Examples were measured for physical properties, weight and the like according to ASTM-related regulations. The results are shown in Table 2 below.

division Example Comparative Example 1 Comparative Example 2 weight 90 94 100 Hardness 101 102 100 300% modulus 102 102 100 The tensile strength 111 103 100 Elongation rate 106 95 100 Braking characteristic 106 102 100 Fuel efficiency 112 104 100

* The measured value of the above-mentioned Example and Comparative Example 1 is a value calculated by taking the value of the rubber specimen of Comparative Example 2 as 100. The lower the numerical value of the physical property value by weight, the better the result.

* The measured values of the above-mentioned Example and Comparative Example 1 are values obtained by taking the value of the rubber specimen of Comparative Example 2 as 100. The numerical values of hardness, 300% modulus, tensile strength, elongation, braking characteristics, The higher the number, the better the result.

Claims (3)

delete A mixture in which a liquid rubber mixed with hollow porous silica powder coated with a surface or a void is hollowed by an organosilane polyol represented by the following formula (1) and a raw rubber,
Wherein the liquid rubber is isoprene or styrene butadiene rubber and has a weight average molecular weight of 3,000 to 60,000.
[Chemical Formula 1]

(Wherein R ¹ is a C ₁ -C ₁₈ alkylene group or a cyclic hydrocarbon, R ² is a C ₁ -C ₁₈ alkyl group or a cyclic hydrocarbon, and ℓ is an integer of 1≤ℓ≤3)
A tire according to claim 2, characterized in that it is made of a tire-capped tread rubber composition comprising a porous reinforcing filler.

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