KR101674452B1 - Tire-rubber composite with excellent tensile strength and appearance - Google Patents

Abstract

The present invention discloses a tire rubber composition excellent in tensile strength (TS, tensile strength), processability and external surface performance.
The tire rubber composition according to the present invention is characterized by comprising silica as raw material rubber made of natural rubber or synthetic rubber and silica as a reinforcing material and liquid rubber as a process aid. According to the present invention, Co-vulcanization with raw rubber is increased, TS (tensile strength) and external surface performance are improved, and compounding processability is secured.

Description

Technical Field [0001] The present invention relates to a tire rubber composition having improved tensile strength and appearance processability,

The present invention relates to a tire rubber composition having improved tensile strength and appearance processability, and more particularly, to a tire rubber composition having improved compound tensile strength and appearance by applying liquid rubber instead of TDAE (Treated Distillate Aromatic Extract) The present invention relates to a tire rubber composition having improved processability.

In order to minimize the load of the equipment during the compounding process of tires and to add a paraffin oil or an aromatic oil added to the process to smooth the process, there is a tendency to restrict the use of environmentally harmful substances in Europe and worldwide .

In addition, when they are blended with rubber, they often have poor tensile strength, which is one of the main characteristics of the compound in terms of performance of the tire, and appearance problems are caused by rapid migration of oil having a low molecular weight to the surface .

For this reason, studies on the present process oil are in progress. However, attempts have been made to use an oil that minimizes the benzene and harmful substances contained in the process oil. However, in this case, a remarkable increase in cost and a decrease in the glass transition temperature there is a problem in that it has a limit to be applied to mass production because it causes deterioration of abrasion resistance property due to remarkable change of glass transition temperature.

Korean Patent Laid-Open No. 2003-0028639 discloses a tire tread rubber composition for a truck bus which is improved in abrasion resistance and abrasion resistance without using an aromatic oil, Instead of the oil, 0.2-0.7 parts by weight of a mixture of 2,2'-dibenzamided diphenyldisulfide and Fe-porphyrazine in a 1: 2 ratio and a liquid isoprene rubber ( liquid isoprene rubber of 3-6 parts by weight, the technical composition is different from that of the present invention.

The object of the present invention is to solve the problems of the prior art as described above, and it is an object of the present invention to provide a rubber composition for a tire, And to provide an improved tire rubber composition.

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

In order to accomplish the above object, the present invention provides a rubber composition comprising 60 to 70 parts by weight of a first rubber composed of 5 to 40% by weight of natural rubber and 60 to 95% by weight of styrene butadiene rubber, 60 parts by weight of silica, And 3 to 6 parts by weight of a second rubber.

According to one embodiment of the present invention, the silica has a specific surface area (BET) of 110 to 200 m 2 / g.

According to another embodiment of the present invention, the liquid rubber is liquid styrene butadiene rubber or liquid polybutadiene rubber.

According to another embodiment of the present invention, the liquid rubber has a molecular weight of 8,000 to 26,000.

Another aspect of the present invention relates to a tire manufactured using the tire rubber composition.

The tire rubber composition according to the present invention can be expected to improve the appearance quality and improve the tensile strength at the same time without using an aromatic oil which is an environmentally harmful substance.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings. However, those skilled in the art will appreciate that various modifications and equivalent embodiments are possible without departing from the scope of the present invention. I will understand that. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

 The present invention relates to a rubber composition comprising 60 to 70 parts by weight of a first rubber consisting of 5 to 40% by weight of natural rubber and 60 to 95% by weight of styrene butadiene rubber, 60 to 60 parts by weight of silica, 3 to 6 parts by weight of a second rubber comprising liquid rubber, To a tire rubber composition.

According to the tire rubber composition according to the present invention, it is possible to improve the appearance quality and the tensile strength at the same time by forming a polymer and Co-vulcanization through application of a liquid rubber used as a process preparation.

The first rubber of the present invention is composed of 5 to 40% by weight of natural rubber and 60 to 95% by weight of styrene butadiene rubber.

The natural rubber is not particularly limited to a rubber used for a tire of a vehicle, and can be widely used depending on applications and functions.

The content of the natural rubber in the first rubber is 5 to 40% by weight. When the content of the natural rubber is less than 5% by weight, the target performance tends not to be attained. When the content of the natural rubber is more than 40% by weight, the low fuel consumption property tends to deteriorate.

In the case of the styrene-butadiene rubber, a solution prepared by a solution polymerization method in which the styrene content is 35 to 45% by weight and the vinyl content in the butadiene is 40 to 60% by weight can be used. The content of the styrene-butadiene rubber in the first rubber is 60 to 95% by weight, and when it is out of the range, the target performance tends not to be reached.

The tire rubber composition of the present invention may contain other rubber components such as modified natural rubber or synthetic rubber as raw rubber in addition to the above-mentioned first rubber.

Examples of synthetic rubbers include styrene butadiene rubber (SBR), polybutadiene rubber (BR), styrene isoprene copolymer rubber, chloroprene rubber (CR), acrylonitrile butadiene rubber (NBR), halogenated butyl (X- And halides of copolymers of butylene and p-methylstyrene. Among them, polybutadiene rubber (BR) and styrene butadiene rubber (SBR) can be suitably used.

The silica of the present invention is used as a reinforcing material in a tire rubber composition and can have a specific surface area (BET) of 110 to 200 m 2 / g. If it is less than 110 m 2 / g, the silica may have a small specific surface area, , The mixing time may be long and the process efficiency may be poor, and the abrasion performance may be deteriorated. On the other hand, if it exceeds 200 m 2 / g, the specific surface area becomes large, and the viscosity of the compounded rubber increases, which may cause problems in the processability of compounding.

The tire rubber composition according to the present invention is characterized in that a liquid rubber is used instead of an aromatic oil as a processing agent.

The addition of the liquid rubber can ensure the processability and improve the durability such as heat resistance, ozone resistance and crack resistance. The liquid rubber is not particularly limited, and for example, liquid styrene butadiene rubber such as LSBR841 manufactured by Kuraray Co., Ltd. or liquid polybutadiene rubber such as LBR305 and LBR307 manufactured by Kuraray can be used.

On the other hand, the liquid rubber may have a molecular weight of 8,000 to 26,000. If the molecular weight is less than 8,000, the molecular weight of the rubber is too small, and the migration speed to the surface is fast, By weight, the molecular weight of the rubber is too large, and the expected effect as a process aid for lowering the viscosity can be reduced.

If the amount of the liquid rubber is less than 3 parts by weight, improvement in processability and appearance quality may not be exhibited. If the amount of the liquid rubber is more than 6 parts by weight, It may deteriorate fairness and lead to adverse effects of rising costs.

In the tire rubber composition of the present invention, it is preferable to blend a silane coupling agent together with silica. As the silane coupling agent, conventionally known silane coupling agents can be used. Examples thereof include bis (3-triethoxysilylpropyl) tetrasulfide, bis (2-triethoxysilylethyl) tetrasulfide, bis (3-trimethoxysilylpropyl) tetrasulfide, bis (2-trimethoxysilylethyl) tetrasulfide, bis (4-trimethoxysilylbutyl) tetrasulfide, bis Bis (4-triethoxysilylbutyl) trisulfide, bis (3-trimethoxysilylpropyl) trisulfide, bis (2-triethoxysilylethyl) trisulfide, Bis (3-triethoxysilylethyl) trisulfide, bis (4-trimethoxysilylethyl) trisulfide, bis 4-triethoxysilylbutyl) disulfide, bis (3-trimethyl (4-trimethoxysilylbutyl) disulfide, 3-trimethoxysilylpropyl-N, N-dimethylthiocarbamoyltetrasulfide, 3 (trimethoxysilylethyl) disulfide, - triethoxysilylpropyl-N, N-dimethylthiocarbamoyltetrasulfide, 2-triethoxysilylethyl-N, N-dimethylthiocarbamoyltetrasulfide, 2-trimethoxysilylethyl- 3-trimethoxysilylpropyl benzothiazolyl tetrasulfide, 3-triethoxysilylpropyl benzothiazole tetrasulfide, 3-trimethoxysilylpropyl methacrylate monosulfide, 3-trimethoxy And silyl propyl methacrylate monosulfide may be used.

The tire rubber composition of the present invention may contain carbon black, and the addition of carbon black can improve the rubber strength and rubber hardness.

On the other hand, the tire rubber composition of the present invention may further comprise a conventional rubber compounding agent.

The rubber compounding agent includes additives such as zinc oxide, stearic acid, sulfur, a vulcanization accelerator, an antioxidant and a pressure sensitive adhesive, and the content of the additive can be easily and arbitrarily adjusted depending on desired physical properties.

The present invention also provides a tire produced using the tire rubber composition.

Hereinafter, preferred embodiments and comparative examples of the present invention will be described. However, the following embodiments are merely preferred embodiments of the present invention, and the present invention is not limited to the following embodiments.

<Examples 1 to 6>

Each component was compounded according to the compositional categories shown in Table 1 below to prepare a tire rubber composition. The tire rubber composition was produced by a conventional tire manufacturing method.

(Unit: parts by weight) Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Raw rubber First rubber Natural rubber ^{1 )} / styrene butadiene rubber ^{2 )} = 7.52 / 58.8 Styrene butadiene rubber ^{3 )} 19.5 19.5 19.5 15.4 19.5 19.5 19.5 19.5 Butadiene rubber ^{4 )} 19.5 19.5 19.5 19.5 19.5 15.4 19.5 15.4 Silica ^{5 )} 60 60 60 60 60 60 60 60 Silane coupling agent ^{6 )} 6.72 6.72 6.72 6.72 6.72 6.72 6.72 6.72 Carbon black ^{7 )} 12 12 12 12 12 12 12 12 TDAE Oil ^{8 )} - 3 - - - - - - Liquid phase
Rubber LSBR841 ^{9 )} - - 3 6 - - - - LBR305 ^{10 )} - - - - 3 6 - - LBR307 ^{11 )} - - - - - - 3 6 Stearic acid 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Zinc oxide 3 3 3 3 3 3 3 3 Vulcanizing agent brimstone 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 CZ ^{12 )} 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 DPG ^{13 )} 1.9 1.9 1.9 1.9 1.9 1.9 1.9 1.9

1) 100R (Kumho Tires)

2) Y031 (Asahi)

3) SBR-1723 (Kumho Petrochemical)

4) BR-01 (Kumho Petrochemical)

5) Premium-200MP (Rhodia, SiO ₂ nH ₂ O (BET 200 m 2 / g))

6) Si-69 (Bis- (3- (triethoxylsilyl) -propyl-tetrasulphide)

7) HP130 (High performance and low hysteresis carbon black)

8) Vivatec500 (molecular weight about 1,000)

9) Liquid styrene-butadiene rubber (average molecular weight: 10,000)

10) Liquid polybutadiene rubber (average molecular weight: 26,000)

11) Liquid polybutadiene rubber (average molecular weight: 8,000)

12) CZ: N-Cyclohexyl-2-Benzothiazol sulfenamide (Tianjin Organic)

13) DPG: 1,3-Diphenylguanidine (Sunshine)

The specimens prepared from the tire rubber compositions of the examples and comparative examples were prepared and tested for physical properties, viscosity and appearance according to the ASTM standard. The results are shown in Table 2 below.

Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Rheo
T40 4.0 4.1 3.9 4.3 4.2 4.5 4.4 4.4 E.C. 12.3 11.8 11.3 11.7 11.3 12.3 11.7 10.9 Mooney T05 13.2 14.0 13.9 15.2 14.9 16.6 15.6 16.3 ML (1 + 4) 125 117 126 114 116 113 121 108
Tensile
Hard's 80 80 81 78 78 78 79 77 100% -M 67 56 55 52 53 53 53 51 T.S. 177 160 171 184 173 184 196 186 E.B. 227 233 250 278 253 273 288 285
Gabo
Tg -0.9 -20.9 -21.0 -18.9 -22.9 -22.9 -22.9 -22.9 Tand @ 0 C 0.263 0.279 0.286 0.300 0.271 0.285 0.262 0.287 Tand @ 70 ℃ 0.113 0.113 0.126 0.138 0.125 0.133 0.121 0.130 DMFC
(5,000) Raw (mm) 19.2 20.9 7.6 6.9 15.2 10.8 17.5 17.4 Column (mm) 8.4 8.5 7.0 6.9 7.6 7.0 8.4 8.4 FTF Cycle 2,170 3,540 6,150 5,460 5,970 7,220 4,470 6,510 DIN Wear amount 0.0710 0.0725 0.0730 0.0735 0.0700 0.0735 0.0680 0.0695 Rebound Index 36.1 36.5 35.0 33.7 38.2 36.0 37.0 36.1

In Table 2, it can be seen that the viscosity (ML (1 + 4)) is high in the case of the comparative example, whereas the viscosity is lower in the examples than the comparative example. The drop in viscosity can ultimately be expected to improve the fairness of the compounding process.

In Table 2, it can be seen that the tensile strength (TS) performance is improved in the Examples in comparison with the Comparative Examples, and the index shows that the larger the value of TS is, the better the crack resistance of the rubber composition is. Lt; RTI ID = 0.0 &gt; of the &lt; / RTI &gt; comparative example.

As shown in the above mixed sheet surface, in the examples of the comparative examples, the improvement in the blending processability was shown to improve the roughness of the end of the sheet, and the sheet surface of the naked eye was also improved as expected.

The tire rubber composition of the present invention can provide a tire improved in appearance quality and tensile strength at the same time without using an aromatic oil which is emerging as an environmentally harmful substance. Therefore, the tire rubber composition is useful for the technical field to which the present invention pertains Can be applied.

Claims (5)

60 to 70 parts by weight of a first rubber comprising 5 to 40% by weight of natural rubber and 60 to 95% by weight of styrene butadiene rubber, 60 to 60 parts by weight of silica, and 3 to 6 parts by weight of a second rubber comprising liquid rubber, The tire rubber composition as claimed in claim 1, The tire rubber composition according to claim 1, wherein the silica has a specific surface area (BET) of 110 to 200 m 2 / g. The tire rubber composition according to claim 1, wherein the liquid rubber is liquid styrene butadiene rubber or liquid polybutadiene rubber. 4. The tire rubber composition according to claim 3, wherein the liquid rubber has a weight average molecular weight of 8,000 to 26,000. A tire produced by using the tire rubber composition according to any one of claims 1 to 4.