JP5253706B2 - Rubber composition and pneumatic tire using the same - Google Patents

Description

  The present invention relates to a rubber composition and a pneumatic tire using the same, and more particularly to a rubber composition that exhibits excellent grip performance when used in a tire tread and a tire using the rubber composition.

  In recent years, with the improvement of automobile performance, road paving and the development of expressway networks, there is an increasing demand for pneumatic tires with high movement performance. The higher this characteristic, the more accurate and safe driving is possible even at high speeds. In particular, grip performance represented by acceleration performance and brake performance is an important required characteristic.

  Conventionally, in order to obtain a high grip performance, a method of using a styrene-butadiene copolymer rubber having a high styrene content, which is a rubber having a high glass transition temperature, in a rubber composition for a tire tread is known. However, this method has a disadvantage that the tan δ value decreases as the rubber temperature increases due to running, and therefore the grip performance decreases as the tire temperature increases.

  In order to eliminate this inconvenience, Patent Document 1 discloses a monomer such as 1,3-butadiene, styrene or isoprene, and diphenyl phosphate such as diphenyl-2-methacryloyloxyethyl phosphate or diphenyl-2-acryloyloxyethyl phosphate. A technique using a copolymer rubber obtained by copolymerizing a methacrylate compound or an acrylate compound containing a group has been reported.

In addition, by using a compound system that is highly filled with process oil and carbon black, a method of increasing the tan δ value of the rubber composition, and adding a certain resin increases the adhesion between the rubber and the road surface. There are also known methods for improving grip performance.
JP 59-187011 A

  The technique described in Patent Document 1 is not only applicable to natural rubber, but also has the disadvantage of impairing inherent properties of polymers such as styrene / butadiene copolymer rubber and polybutadiene rubber depending on production conditions. Although the grip performance is improved in the method using a compound system that is highly filled with carbon black, the fracture characteristics and wear resistance are significantly reduced, so there is a limit to high filling, and it is difficult to obtain the required level of high grip performance. There was an inconvenience.

  In addition, in the method of improving grip performance by adding a certain kind of resin, generally, the higher the grip performance, the higher the adhesion with the metal mixer and metal roll existing in the manufacturing process, Since there is a tendency to hinder workability, it is actually difficult to improve the grip by improving the resin.

  Accordingly, an object of the present invention is to provide a rubber composition capable of obtaining a high grip performance without impairing various tire performances such as fracture characteristics and wear resistance and factory workability when used in a tire tread, and a rubber composition thereof. It is to provide a used tire.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by combining an inorganic metal compound and a phenol resin as a rubber composition, and have completed the present invention. .

That is, the rubber composition of the present invention comprises at least one rubber component selected from the group consisting of natural rubber, synthetic polyisoprene rubber, polybutadiene rubber and styrene-butadiene copolymer rubber, and the rubber component,
At least one inorganic selected from the group consisting of calcium oxide, calcium sulfide, calcium hydroxide, calcium halide, calcium carbonate, calcium sulfate, magnesium oxide, magnesium sulfide, magnesium hydroxide, magnesium halide, magnesium carbonate, and magnesium sulfate It contains a metal compound and at least one phenol resin, and the total amount of the inorganic metal compound is 0.1 to 10 parts by mass (excluding 10 parts by mass) with respect to 100 parts by mass of the rubber component. It is characterized by being.

  The pneumatic tire of the present invention is characterized in that the rubber composition of the present invention is used for a tread.

  Tires that use the rubber composition of the present invention in the tread should greatly improve grip performance compared to conventional tires without impairing tire performance and factory workability such as fracture characteristics and wear resistance. Can do.

  Hereinafter, the present invention will be described in detail based on embodiments. The rubber composition of the present invention is formed by combining a rubber component, at least one inorganic metal compound represented by the above general formula (I), and at least one phenol resin, As the rubber component, natural rubber and synthetic rubber may be used alone or in combination. Examples of the synthetic rubber include synthetic polyisoprene rubber, polybutadiene rubber, and styrene / butadiene copolymer rubber.

  In the compound represented by the above general formula (I), X is preferably oxygen, sulfur, hydroxyl group, halogen group, carbonic acid, sulfuric acid or stearic acid, and M is magnesium, calcium, strontium or barium. Specific examples of the compound represented by the above formula (I) include beryllium oxide, beryllium chloride, beryllium sulfate, beryllium nitrate, beryllium sulfide, magnesium oxide, magnesium hydroxide, magnesium acetate, magnesium hydrogen sulfate, magnesium sulfate, fluoride. Magnesium, magnesium chloride, magnesium bromide, magnesium iodide, magnesium carbonate, magnesium hydrogen carbonate, magnesium benzoate, magnesium chromate, magnesium phosphate, magnesium hydrogen phosphate, magnesium nitrate, magnesium lactate, magnesium oxalate, perchloric acid Magnesium, magnesium stearate, magnesium succinate, magnesium sulfide, calcium oxide, calcium hydroxide, calcium sulfate, calcium acetate, calcium benzoate, calcium carbonate Calcium phosphate, calcium hydrogen phosphate, calcium dihydrogen phosphate, calcium fluoride, calcium chloride, calcium bromide, calcium iodide, calcium citrate, calcium formate, calcium gluconate, calcium glycerophosphate, calcium phosphinate, calcium lactate , Calcium molybdate, calcium nitrate, calcium nitrite, calcium oleate, calcium oxalate, calcium palmitate, calcium peroxide, calcium propionate, calcium silicate, calcium stearate, calcium tartrate, calcium thiocyanate, calcium tungstate, pantothene Calcium oxide, calcium sulfide, strontium acetate, strontium fluoride, strontium chloride, strontium bromide, iodide Strontium, strontium carbonate, strontium formate, strontium hydroxide, strontium oxide, strontium nitrate, strontium oxalate, strontium sulfate, strontium sulfide, barium acetate, barium aluminate, barium borate, barium fluoride, barium chloride, barium bromide, Barium iodide, barium carbonate, barium chlorate, barium chromate, barium phosphate, barium hydrogen phosphate, barium hydroxide, barium lactate, barium molybdate, barium nitrate, barium oxalate, barium perchlorate, barium peroxide , Barium stearate, barium sulfate, barium sulfite, barium thiocyanate, barium thiosulfate, barium titanate, barium sulfide, radium oxide, radium hydroxide, radium fluoride, chloride Radium, radium bromide, radium iodide, radium carbonate, radium sulfate, radium sulfide, aluminum oxide, aluminum hydroxide, aluminum chloride, aluminum bromide, aluminum acetate, aluminum sulfate, aluminum borate, aluminum iodide, aluminum lactate, Aluminum laurate, aluminum nitrate, aluminum oleate, aluminum phosphate, aluminum fluoride, iron oxide, iron hydroxide, iron fluoride, iron chloride, iron bromide, iron iodide, iron lactate, iron nitrate, iron sulfate, Iron sulfide, iron acetate, copper oxide, copper hydroxide, copper sulfate, copper acetate, copper chloride, copper fluoride, copper bromide, copper iodide, copper carbonate, copper naphthenate, copper oleate, copper oxalate, phosphorus Copper oxide, copper nitrate, copper stearate, tin oxide, tin hydroxide, tin fluoride, tin chloride, tin bromide, tin iodide Tin oxalate, titanium oxide, titanium chloride, titanium sulfate, vanadium oxide, vanadium sulfate, manganese oxide, manganese sulfate, manganese bromide, manganese acetate, manganese benzoate, manganese carbonate, manganese chloride, manganese oxalate, manganese nitrate, etc. Can be mentioned.

  Further, as the phenol resin, both novolak type and resol type phenol resins can be used. Further, modified phenolic resins and the like are also effective. Specific examples of the phenol resin monomer include phenol, alkylphenols such as cresol, and resole. Specific examples of those copolymerized with these monomers include formaldehyde, acetylene, and ethylene. However, it is not limited to these. Preferable phenol resins include pt-butylphenol / formaldehyde resin and pt-butylphenol / acetylene resin, and more preferably pt-butylphenol / acetylene resin.

  In the rubber composition of the present invention, the compounding amount of the compound represented by the formula (I) is preferably 0.1 to 20 parts by mass, more preferably 0.1 to 100 parts by mass of the rubber component. -10 parts by mass. When the blending amount is less than 0.1 parts by mass, a sufficient effect is not necessarily obtained. On the other hand, when it exceeds 20 parts by mass, the desired performance is obtained, but various physical properties after vulcanization are adversely affected. It is possible. The blending amount of the phenol resin is preferably 0.1 to 200 parts by mass with respect to 100 parts by mass of the rubber component.

  In the rubber composition of the present invention, the reinforcing filler is not particularly limited, and one or more of carbon black, silica, alumina, aluminum hydroxide, calcium carbonate, titanium oxide, and the like are used. Carbon black can be used preferably.

  In the present invention, in addition to the rubber component, reinforcing filler, and resin described above, compounding agents such as softeners, anti-aging agents, coupling agents, vulcanizations are commonly used in the rubber industry. An accelerator, a vulcanization acceleration aid, a vulcanizing agent, and the like can be blended within a range of blending amounts that are normally used, if necessary.

  The rubber composition of the present invention is obtained by kneading using a kneader such as an open kneader such as a roll or a closed kneader such as a Banbury mixer, and vulcanized after molding to produce various rubber products. Applicable. In particular, it can be used for tire applications such as tire treads, under treads, carcass, sidewalls, bead portions, etc., and among them, it is preferably used as rubber for tire treads.

  EXAMPLES Next, although an Example demonstrates this invention still in detail, this invention is not limited at all by this example.

Examples 1-7, Comparative Examples 1-3
A rubber composition was blended and formulated at the ratio shown in Table 1 below, and a tire prepared according to a conventional method was applied to a tire tread to prepare a test tire. In addition, the numerical value in a table | surface is a mass part. The tire size was 225 / 40R18. The grip performance of the test tire was evaluated as follows by running on a test course of 4.4 km per lap. The lap times from the 10th to the 20th lap of each Example and Comparative Example were measured, the average lap time was divided by the tire time of Comparative Example 1, and the value obtained by multiplying the reciprocal by 100 was displayed as an index. The larger the value, the higher the grip, and the smaller the value, the poorer the grip. The respective evaluation results are also shown in Table 1.

From Table 1 above, it can be seen that each example has improved grip performance compared to the comparative example. In particular, it was confirmed that Examples 2, 3, 4 and 5 were more excellent.

Claims (4)

At least one rubber component selected from the group consisting of natural rubber, synthetic polyisoprene rubber, polybutadiene rubber and styrene-butadiene copolymer rubber, and the rubber component,
At least one inorganic selected from the group consisting of calcium oxide, calcium sulfide, calcium hydroxide, calcium halide, calcium carbonate, calcium sulfate, magnesium oxide, magnesium sulfide, magnesium hydroxide, magnesium halide, magnesium carbonate, and magnesium sulfate It contains a metal compound and at least one phenol resin, and the total amount of the inorganic metal compound is 0.1 to 10 parts by mass (excluding 10 parts by mass) with respect to 100 parts by mass of the rubber component. A rubber composition characterized by being. The rubber composition of claim 1 wherein the phenolic resin is a p-t-butylphenol-acetylene resin. The rubber composition according to any one of claims 1 and 2 , wherein the total amount of the phenolic resin is 0.1 to 200 parts by mass with respect to 100 parts by mass of the rubber component. A pneumatic tire using the rubber composition according to any one of claims 1 to 3 for a tread.