Rubber composition

Abstract

The present invention provides a rubber composition which simultaneously realizes wet skid resistance, low rolling resistance, and cut resistance. The rubber composition is characterized by compounding 1 to 150 parts by mass of a mixed resin in 100 parts by mass of a diene rubber, the mixed resin being composed of 1 to 99 mass% of a hydrogenated styrene resin and 99 to 1 mass% of an aromatic modified terpene resin.

Description

Technical Field

[0001] This invention relates to rubber compositions that simultaneously achieve wet grip, low rolling resistance, and cut resistance. Background Technology

[0002] In recent years, as tires become more environmentally friendly, they need to have excellent fuel economy while ensuring that basic performance characteristics such as grip and durability are equal to or better than existing products. However, fuel economy and grip are contradictory, and therefore it is generally believed that they are difficult to achieve simultaneously.

[0003] Patent Document 1 proposes a method of incorporating an aromatic modified terpene resin into a rubber composition constituting a tire, thereby improving wet grip and reducing rolling resistance. Patent Document 2 proposes a method of incorporating a hydrogenated styrene resin into a rubber composition, thereby improving wet grip and reducing rolling resistance. However, in the inventions described in Patent Documents 1 and 2, improving machinability is difficult in addition to wet grip and low rolling resistance. That is, a rubber composition that simultaneously achieves wet grip, low rolling resistance, and machinability has not yet been developed.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2009-138157

[0007] Patent Document 2: Japanese Patent Application Publication No. 2019-131795 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] The purpose of this invention is to provide a rubber composition that simultaneously achieves wet grip, low rolling resistance, and cut resistance.

[0010] Methods for solving problems

[0011] The rubber composition of the present invention that achieves the above-mentioned objective is characterized in that 1 to 150 parts by weight of a mixed resin are incorporated in 100 parts by weight of diene rubber, said mixed resin being composed of 1 to 99% by weight of hydrogenated styrene resin and 99 to 1% by weight of aromatic modified terpene resin.

[0012] Invention Effects

[0013] According to the rubber composition of the present invention, by incorporating 1 to 150 parts by weight of a mixed resin containing 1 to 99% by weight of hydrogenated styrene resin and 99 to 1% by weight of aromatic modified terpene resin into 100 parts by weight of diene rubber, wet grip, low rolling resistance, and cutability can be simultaneously achieved. Furthermore, the hydrogenation rate of the hydrogenated styrene resin can be 40 to 90%, and the rubber composition can also incorporate 5 to 300 parts by weight of inorganic filler into 100 parts by weight of the diene rubber.

[0014] For rubber compositions used in studless or studded tires, the diene rubber comprises natural rubber and butadiene rubber, the average glass transition temperature of the diene rubber can be -100°C to -80°C, and 10 to 90 parts by weight of silica can be added.

[0015] For the rubber composition used in winter tires, the diene rubber includes styrene-butadiene rubber and butadiene rubber, and the average glass transition temperature of the diene rubber can be -100°C to -50°C. In addition, 90 to 180 parts by weight of silica can be added.

[0016] For rubber compositions used in all-season tires, the diene rubber includes styrene-butadiene rubber, the average glass transition temperature of the diene rubber can be -80°C to -20°C, and 10 to 90 parts by weight of silica can be added.

[0017] For rubber compositions used in high-performance tires or race tires, the diene rubber includes styrene-butadiene rubber, the average glass transition temperature of which can be higher than -50°C and lower than -20°C, and may also contain 90 to 180 parts by weight of silica.

[0018] For the rubber composition for low fuel consumption tires, the diene rubber includes styrene-butadiene rubber, the average glass transition temperature of the diene rubber can be -40°C to -20°C, and in addition, more than 10 parts by weight and less than 90 parts by weight of silica can be added.

[0019] The above-described rubber composition is suitable for constituting the tread of a tire. Tires with a tread formed using the rubber composition of the present invention can simultaneously achieve wet grip, low rolling resistance, and cut resistance. Detailed Implementation

[0020] The rubber composition includes diene rubbers commonly used in tires. Examples of diene rubbers include natural rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, styrene-isoprene rubber, isoprene-butadiene rubber, ethylene-propylene-diene copolymer rubber, chloroprene rubber, and acrylonitrile-butadiene rubber. These diene rubbers can be modified using one or more functional groups. The type of functional group is not particularly limited, and examples include epoxy, carboxyl, amino, hydroxyl, alkoxy, silyl, alkoxysilyl, amide, oxysilyl, silanol, isocyanate, isothiocyanate, carbonyl, and aldehyde groups.

[0021] Natural rubber, butadiene rubber, and styrene-butadiene rubber are all acceptable rubbers commonly used in rubber compositions; there are no particular restrictions. Combining natural rubber ensures the tire's cut resistance. Furthermore, combining butadiene rubber ensures the tire's performance on ice and snow. Additionally, combining styrene-butadiene rubber ensures the tire's wet grip.

[0022] By incorporating 1 to 150 parts by weight of a mixed resin into 100 parts by weight of diene rubber, the rubber composition can simultaneously achieve wet grip, low rolling resistance, and cutability. If the mixed resin is less than 1 part by weight, the simultaneous effects of wet grip, low rolling resistance, and cutability cannot be sufficiently achieved. If the mixed resin is greater than 150 parts by weight, abrasion resistance and processability decrease. Preferably, 3 to 100 parts by weight, more preferably 5 to 50 parts by weight, of the mixed resin can be incorporated.

[0023] The mixed resin is a mixture of hydrogenated styrene resin and aromatic modified terpene resin. The mixed resin can be prepared by pre-mixing the hydrogenated styrene resin and aromatic modified terpene resin, or by separately adding them to a mixing mill for manufacturing rubber compositions, or by adding them together with other raw materials. The hydrogenated styrene resin and aromatic modified terpene resin respectively improve wet grip and low rolling resistance. However, neither alone provides an improvement in cutting resistance. Surprisingly, by using both hydrogenated styrene resin and aromatic modified terpene resin in combination, in addition to improving wet grip and low rolling resistance, an improvement in cutting resistance is also achieved. In 100% by mass of the mixed resin, the hydrogenated styrene resin is 1-99% by mass, and the aromatic modified terpene resin is 99-1% by mass. Preferably, the hydrogenated styrene resin is 5-95% by mass, and the aromatic modified terpene resin is 95-5% by mass; more preferably, the hydrogenated styrene resin is 10-90% by mass, and the aromatic modified terpene resin is 90-10% by mass.

[0024] Hydrogenated styrene resin is a resin obtained by hydrogenating (hereinafter sometimes simply referred to as "hydrogenation") styrene resin formed from styrene monomers. By hydrogenating the styrene resin, the aromatic rings from styrene are reduced, thus improving the dispersibility in diene rubbers and promoting crosslinking of the diene rubbers. This results in more uniform crosslinking positions between rubber polymers and increases the modulus of the vulcanized rubber composition. Furthermore, the crosslinking of the rubber becomes more uniform and tighter, thereby improving durability.

[0025] Styrene resin, the basis of hydrogenated styrene resin, can be obtained by addition polymerization of styrene. Addition polymerization can be carried out using known methods, such as solution polymerization using an active anionic polymerization catalyst, methods using a cationic polymerization catalyst, or methods using a free radical polymerization initiator.

[0026] Hydrogenated styrene resin can be obtained by hydrogenating the aromatic rings in styrene resin. The method of hydrogenation is a known prior art and is not particularly limited. The hydrogenation rate of the aromatic rings is not particularly limited, but is 0.1% to 100%, preferably 1% to 95%, more preferably 40% to 90%, and even more preferably 50% to 80%. When the hydrogenation rate of the aromatic rings is less than 0.1%, the properties resulting from hydrogenation cannot be fully exhibited. Here, the hydrogenation rate (hydrogenation ratio) of the aromatic rings is a value calculated using the following formula based on the peak height of the absorbance from styrene obtained by IR (infrared spectrophotometer).

[0027] Hydrogenation rate (%) = {(CD) / C} × 100

[0028] C: Height of the absorbance peak from the aromatic ring before hydrogenation

[0029] D: Height of the absorbance peak from the aromatic ring after hydrogenation.

[0030] It should be noted that hydrogenated styrene resin can be used alone or in combination with two or more types.

[0031] Regarding the molecular weight of the hydrogenated styrene resin, the weight-average molecular weight (Mw) calculated based on polystyrene by gel permeation chromatography (GPC) is 500 to 10,000, preferably 1,000 to 7,000, and more preferably 1,500 to 5,000. When the weight-average molecular weight is less than 500, the durability of the rubber composition is poor; conversely, if the weight-average molecular weight is greater than 10,000, the improvement in the grip of the rubber composition is sometimes poor.

[0032] Aromatic modified terpene resins are copolymers of terpenes and aromatic compounds. Examples of terpenes include α-pinene, β-pinene, dipentene, and limonene. Examples of aromatic compounds include styrene, α-methylstyrene, vinyltoluene, and indene. The content of the aromatic compound in the aromatic modified terpene resin is preferably 10–50% by mass, more preferably 12–45% by mass. By incorporating aromatic modified terpene resins into diene-based rubbers, the dynamic viscoelasticity of the rubber composition can be modified, improving wet grip and thermal properties.

[0033] The softening point of the aromatic modified terpene resin is not particularly limited, but is preferably 60°C to 150°C, more preferably 80°C to 130°C. If the softening point of the aromatic modified terpene resin is below 60°C, there is a concern about reduced wet grip. If the softening point of the aromatic modified terpene resin is above 150°C, there is a concern about deterioration in low rolling resistance. In this specification, the softening point of the aromatic modified terpene resin is determined based on JIS K6220-1 (ring and ball method).

[0034] The rubber composition may incorporate 5 to 300 parts by weight, more preferably 30 to 150 parts by weight, of an inorganic filler in 100 parts by weight of diene rubber. By incorporating an inorganic filler, tire durability, such as cut resistance, and handling stability can be ensured. Examples of inorganic fillers include carbon black, silica, calcium carbonate, magnesium carbonate, talc, clay, mica, alumina, aluminum hydroxide, titanium dioxide, and calcium sulfate. Two or more inorganic fillers may be used alone or in combination.

[0035] The carbon black used is any type commonly used in rubber compositions; there are no particular limitations. The nitrogen adsorption specific surface area of ​​the carbon black is preferably 50–160 m². 2 / g, more preferably 80-150m 2 / g, more preferably 100-130m 2 / g. By making the nitrogen adsorption specific surface area 50m² 2 A nitrogen adsorption surface area of ​​160 m² / g or higher ensures tire durability. 2 Below / g, heat generation can be reduced, thus ensuring low rolling resistance. The nitrogen adsorption specific surface area of ​​carbon black can be calculated according to JIS K6217-2.

[0036] Carbon black can be added to 100 parts by weight of diene rubber, preferably 5 to 100 parts by weight, more preferably 5 to 80 parts by weight. Adding 5 or more parts by weight of carbon black ensures tire durability. Additionally, it ensures rigidity and reduces heat generation. By using less than 100 parts by weight of carbon black, low rolling resistance is ensured. Two or more types of carbon black can be used in combination.

[0037] In rubber compositions, silica can be incorporated to further reduce heat generation. Examples of silica include wet silica (hydrated silicic acid), dry silica (anhydrous silicic acid), calcium silicate, and aluminum silicate; these can be used alone or in combination of two or more. Alternatively, surface-treated silica obtained by surface-treating the silica surface using a silane coupling agent can also be used.

[0038] In rubber compositions, it is preferable to use a silane coupling agent in combination with silica to ensure good dispersion of silica. The silane coupling agent can be of a type commonly used in combination with silica. The silane coupling agent can be used in an amount preferably 5-15% by mass, more preferably 8-12% by mass, of the silica.

[0039] The rubber composition may be formulated with various additives commonly used in rubber compositions, such as vulcanizing or crosslinking agents, vulcanization accelerators, anti-aging agents, plasticizers, processing aids, liquid polymers, and thermosetting resins, to a extent that does not impair the objectives of the present invention. Furthermore, these additives can be used to prepare the rubber composition by conventional methods of compounding and vulcanization or crosslinking. The amounts of these additives can be set to conventional compounding amounts, as long as they do not deviate from the objectives of the present invention.

[0040] Rubber compositions for studless and studded tires

[0041] The rubber composition suitable for constituting the tread of studless or studded tires and solving the problem of the present invention is prepared by adding 1 to 150 parts by weight of a mixed resin to 100 parts by weight of a diene rubber comprising natural rubber and butadiene rubber, wherein the average glass transition temperature of the diene rubber is preferably -100°C to -80°C. Additionally, 10 to 90 parts by weight of silica may be added to 100 parts by weight of the diene rubber.

[0042] In 100% by mass diene rubber, preferably 20-80% by mass, more preferably 30-70% by mass, of natural rubber may be contained. By containing natural rubber within this range, tire durability can be ensured.

[0043] Of 100% by weight of diene-based rubber, preferably 20-60% by weight, more preferably 30-50% by weight, of butadiene rubber may be included. By including butadiene rubber in this range, ice performance can be ensured. The rubber composition constituting the tread of studless or studded tires may include other diene-based rubbers in addition to natural rubber and butadiene rubber.

[0044] The average glass transition temperature of diene rubber is preferably -100°C to -80°C, more preferably -90°C to -80°C. Maintaining the average glass transition temperature within this range ensures tire durability and ice performance. In this specification, the average glass transition temperature of the diene rubber can be calculated by weighted averaging the glass transition temperatures of each diene rubber contained therein with their respective contents. Furthermore, the glass transition temperature of the diene rubber can be determined by differential scanning calorimetry (DSC) using a heating rate of 20°C / min to measure the temperature spectrum, setting the temperature as the midpoint of the transition region.

[0045] Rubber compositions suitable for studless or studded tires may incorporate 10 to 90 parts by weight, more preferably 20 to 80 parts by weight, of silica in 100 parts by weight of diene rubber. By including silica in this range, wet grip performance and tire durability can be ensured.

[0046] Rubber Compositions for Winter Tires

[0047] The rubber composition suitable for constituting the tread of winter tires and solving the problem of the present invention is prepared by adding 1 to 150 parts by weight of a mixed resin to 100 parts by weight of a diene rubber comprising styrene-butadiene rubber and butadiene rubber. The average glass transition temperature of the diene rubber is preferably -100°C to -50°C. Additionally, 90 to 180 parts by weight of silica can be added to 100 parts by weight of the diene rubber.

[0048] In 100% by mass of diene-based rubber, preferably 30-80% by mass, more preferably 40-70% by mass of styrene-butadiene rubber may be contained. By containing styrene-butadiene rubber within this range, wet grip performance can be ensured.

[0049] In 100% by mass of diene-based rubber, it may contain preferably 20-50% by mass, more preferably 25-45% by mass of butadiene rubber. By containing butadiene rubber within this range, snow performance can be ensured. The rubber composition constituting the tread of a winter tire may include other diene-based rubbers such as butadiene rubber in addition to styrene-butadiene rubber and butadiene rubber.

[0050] The average glass transition temperature of diene-based rubbers is preferably -100°C to -50°C, more preferably -70°C to -50°C. By keeping the average glass transition temperature within this range, wet grip performance and snow performance can be ensured.

[0051] Rubber compositions suitable for winter tires may incorporate 90 to 180 parts by weight, more preferably 95 to 150 parts by weight, of silica in 100 parts by weight of diene-based rubber. By including silica in this range, wet grip performance can be ensured.

[0052] Rubber compositions for all-season tires

[0053] The rubber composition suitable for constituting the tread of all-season tires and solving the problem of the present invention is prepared by adding 1 to 150 parts by weight of a mixed resin to 100 parts by weight of a diene rubber containing styrene-butadiene rubber. The average glass transition temperature of the diene rubber is preferably -80°C to -20°C. In addition, 10 to 90 parts by weight of silica can be added to 100 parts by weight of the diene rubber.

[0054] In 100% by mass of diene-based rubber, preferably 30-80% by mass, more preferably 40-70% by mass of styrene-butadiene rubber may be included. By including styrene-butadiene rubber in this range, wet grip performance can be ensured. The rubber composition constituting the tread of an all-season tire may include other diene-based rubbers such as butadiene rubber in addition to styrene-butadiene rubber.

[0055] The average glass transition temperature of diene-based rubber is preferably -80°C to -20°C, more preferably -80°C to -40°C, and even more preferably -70°C to -50°C. By keeping the average glass transition temperature within this range, snow performance can be ensured.

[0056] The rubber composition suitable for all-season tires may contain 10 to 90 parts by weight, more preferably 20 to 80 parts by weight, of silica in 100 parts by weight of diene rubber. By including silica in this range, wet grip performance and tire durability can be ensured.

[0057] Rubber compositions for high-performance tires or racing tires

[0058] The rubber composition suitable for constituting the tread of high-performance tires and racing tires, and which solves the problem of the present invention, is prepared by compounding 1 to 150 parts by weight of a mixed resin in 100 parts by weight of a diene rubber comprising styrene-butadiene rubber. The average glass transition temperature of the diene rubber is preferably higher than -50°C and lower than -20°C. Additionally, 90 to 180 parts by weight of silica can be compounded in 100 parts by weight of the diene rubber.

[0059] In 100% by mass of diene-based rubber, preferably 50-100% by mass, more preferably 65-95% by mass of styrene-butadiene rubber may be included. By including styrene-butadiene rubber in this range, dry grip can be improved. The rubber composition constituting the tread of high-performance tires and racing tires may include other diene-based rubbers such as butadiene rubber in addition to styrene-butadiene rubber.

[0060] The average glass transition temperature of diene-based rubbers is preferably higher than -50°C and lower than -20°C, more preferably -40°C to -30°C. By keeping the average glass transition temperature within this range, dry grip performance can be ensured.

[0061] Rubber compositions suitable for high-performance tires and racing tires may incorporate 90 to 180 parts by weight, more preferably 95 to 150 parts by weight, of silica in 100 parts by weight of diene-based rubber. By including silica in this range, wet grip performance can be ensured.

[0062] Rubber compositions for low-fuel-consumption tires

[0063] The rubber composition suitable for constituting the tread of a low-fuel-consumption tire with excellent fuel efficiency, and which solves the problem of the present invention, is prepared by compounding 1 to 150 parts by weight of a mixed resin in 100 parts by weight of a diene-based rubber containing styrene-butadiene rubber. The average glass transition temperature of the diene-based rubber is preferably -40°C to -20°C. Additionally, 10 parts by weight or more and less than 90 parts by weight of silica may be compounded in 100 parts by weight of the diene-based rubber.

[0064] In 100% by mass of diene-based rubber, preferably 40-100% by mass, more preferably 60-95% by mass of styrene-butadiene rubber may be included. By including styrene-butadiene rubber in this range, wet grip performance can be ensured. The rubber composition constituting the tread of the low-fuel-consumption tire may include other diene-based rubbers such as butadiene rubber in addition to styrene-butadiene rubber.

[0065] The average glass transition temperature of diene-based rubbers is preferably -40°C to -20°C, more preferably -40°C to -30°C. By keeping the average glass transition temperature within this range, wet grip performance and low rolling resistance can be ensured.

[0066] The rubber composition suitable for low-fuel-consumption tires may contain 10 or more but less than 90 parts by weight, more preferably 20 to 80 parts by weight, of silica in 100 parts by weight of diene rubber. By containing silica in this range, wet grip performance and low rolling resistance can be ensured.

[0067] The aforementioned rubber composition is preferably a tire tread rubber composition, suitable for constituting the tread portion of a tire. Tires with a tread portion constructed using the rubber composition of the present invention can simultaneously achieve wet grip, low rolling resistance, and cut resistance. It should be noted that the tire can be any type of tire, including pneumatic tires and non-pneumatic tires.

[0068] The present invention will be further illustrated below with reference to examples, but the scope of the present invention is not limited to these examples.

[0069] Example

[0070] Using the compounding agents shown in Table 7 as general compounding agents, for rubber compositions (Examples 1-13, Standard Examples 1-6, Comparative Examples 1-18) composed of the compounding agents shown in Tables 1-6, the components except for sulfur and vulcanization accelerator were mixed in a 1.7L closed Banbury mixer for 5 minutes, then discharged from the mixer and cooled to room temperature. This mixture was then fed into the aforementioned 1.7L closed Banbury mixer, and sulfur and vulcanization accelerator were added and mixed to prepare the rubber composition. Furthermore, the compounding amounts of the compounding agents listed in Table 7 are expressed as parts by mass relative to 100 parts by mass of the diene rubber listed in Tables 1-6.

[0071] Furthermore, using the obtained rubber composition, vulcanized rubber sheets were prepared by vulcanizing at 160°C for 20 minutes in a mold measuring 15cm × 15cm × 0.2cm. The dynamic viscoelasticity was measured using the method described below as an indicator of wet grip and low rolling resistance. For the rubber sample used to evaluate cut resistance, a mold measuring 9.5cm × 9.5cm on the upper surface, 10.6cm × 10.6cm on the lower surface, and 3.9cm in height was prepared by pressurizing and vulcanizing the obtained rubber composition at 160°C for 20 minutes. The sample was evaluated using the method described below.

[0072] wet grip

[0073] Using a viscoelastic spectrometer manufactured by Toyo Seiki Co., Ltd., the dynamic viscoelasticity of the vulcanized rubber sheet obtained above was measured under the conditions of initial strain 10%, amplitude ±2%, and frequency 20Hz, and the tanδ at 0℃ was determined. The results are shown in the "Wet Grip" column of Tables 1-6: Table 1 uses the index of Standard Example 1 set to 100; Table 2 uses the index of Standard Example 2 set to 100; Table 3 uses the index of Standard Example 3 set to 100; Table 4 uses the index of Standard Example 4 set to 100; Table 5 uses the index of Standard Example 5 set to 100; and Table 6 uses the index of Standard Example 6 set to 100. A higher index indicates better wet grip.

[0074] Low rolling resistance

[0075] Using a viscoelastic spectrometer manufactured by Toyo Seiki Co., Ltd., the dynamic viscoelasticity of the vulcanized rubber sheet obtained above was measured under the conditions of initial strain 10%, amplitude ±2%, and frequency 20Hz, and the tanδ at 60℃ was determined. The results are denoted in Table 1 as the index with the value of Standard Example 1 set to 100, in Table 2 as the index with the value of Standard Example 2 set to 100, in Table 3 as the index with the value of Standard Example 3 set to 100, in Table 4 as the index with the value of Standard Example 4 set to 100, in Table 5 as the index with the value of Standard Example 5 set to 100, and in Table 6 as the index with the value of Standard Example 6 set to 100, and are shown in the "Low Rolling Resistance" column of Tables 1-6. A smaller index indicates lower rolling resistance and better low rolling resistance.

[0076] Machinability

[0077] For the rubber samples used in the cutting resistance evaluation above, a needle with a load of 49 N (tip angle 90°, diameter φ 4 mm) was dropped from a height of 15 cm into the rubber sample, and the penetration depth was measured. A smaller penetration depth indicated higher and better cutting resistance. Based on the results, the reciprocal of the penetration depth was calculated and denoted as the index of Standard Example 1 (set to 100) in Table 1, Standard Example 2 (set to 100) in Table 2, Standard Example 3 (set to 100) in Table 3, Standard Example 4 (set to 100) in Table 4, Standard Example 5 (set to 100) in Table 5, and Standard Example 6 (set to 100) in Table 6, and is shown in the "Cutting Resistance" column of Tables 1-6. A larger index indicates a smaller penetration depth and better cutting resistance.

[0078] [Table 1]

[0079]

[0080] [Table 2]

[0081]

[0082] [Table 3]

[0083]

[0084] [Table 4]

[0085]

[0086] [Table 5]

[0087]

[0088] [Table 6]

[0089]

[0090] The types of raw materials used are listed in Tables 1-6 below.

[0091] • NR: Natural rubber, SIR-20, glass transition temperature is -65℃

[0092] • SBR-1: Styrene-butadiene rubber, Asahi Kasei Corporation, Tableden E581, glass transition temperature -28℃

[0093] • SBR-2: Styrene-butadiene rubber, manufactured by Zion Corporation of Japan, Nipol 1723, with a glass transition temperature of -53℃.

[0094] ·BR: Butadiene rubber, Ube Industries, Ltd. UBEPOL 1220, glass transition temperature -106℃

[0095] ·Carbon black: Nippon Steel Co., Ltd. #300IH

[0096] • Silica: Solvay ZEOSIL 1165MP

[0097] • Silane coupling agent: Si69, manufactured by Evonik Degussa, bis(triethoxysilylpropyl)tetrasulfide

[0098] • Aromatic modified terpene resin: TO-125 manufactured by Yasuharake Mikaru Co., Ltd., softening point 125℃

[0099] • Unhydrogenated styrene resin: Styrene resin, Yasuharake Mikaru Co., Ltd., YS Regin SX100, softening point 100℃

[0100] • Hydrogenated styrene resin-1: Hydrogenated styrene resin with a hydrogenation rate of 70% and a softening temperature of 101℃

[0101] • Hydrogenated styrene resin-2: Hydrogenated styrene resin with a hydrogenation rate of 30% and a softening temperature of 95℃.

[0102] • Hydrogenated styrene resin-3: Hydrogenated styrene resin with a hydrogenation rate of 95% and a softening temperature of 116℃.

[0103] Modulation of hydrogenated styrene resin-1

[0104] 500g of toluene and 15g of aluminum chloride catalyst were added to a flask and stirred under a nitrogen stream. After 1 hour, 500g of styrene was added dropwise. The temperature inside the flask was maintained at 20°C during this process. After the addition was complete, the catalyst was removed by washing with water. The resulting reaction oil was then subjected to vacuum distillation to remove the toluene, yielding 500g of styrene resin. The weight-average molecular weight was 2,500, and the softening point was 101°C.

[0105] 500g of the obtained styrene resin, 1000g of cyclohexane, and 10g of powdered stabilized nickel catalyst were added to a high-pressure reactor. The reactor was then sealed, and the atmosphere was purged with nitrogen before hydrogen was introduced. The reactor was then heated to 150°C with the hydrogen pressure set at 50 kg / cm². 2 The pressure is maintained at 50 kg / cm² while replenishing the absorbed hydrogen. 2 The reaction proceeded for 6 hours. After the reaction, the catalyst was filtered, and the solvent was removed by vacuum distillation to obtain a hydrogenated styrene resin. The softening point was 101℃, and the hydrogenation rate of the aromatic rings was 70%.

[0106] Modulation of hydrogenated styrene resin-2

[0107] The hydrogenation reaction was carried out in the same manner as hydrogenated styrene resin-1 for 3 hours. The softening point was 101°C, and the hydrogenation rate of the aromatic rings was 30%.

[0108] Modulation of hydrogenated styrene resin-3

[0109] The hydrogenation reaction was carried out in the same manner as hydrogenated styrene resin-1 for 8 hours. The softening point was 116°C, and the hydrogenation rate of the aromatic rings was 95%.

[0110] [Table 7]

[0111]

[0112] The types of raw materials used are listed in Table 7 below.

[0113] ·Fragrance oil: Showa Seru Oil Co., Ltd.'s Setoro No. 4 S

[0114] • Processing aid: HT207 manufactured by Stracto-Iro Co., Ltd.

[0115] Anti-aging agent: 6 PPD manufactured by Frekisys.

[0116] Wax: OZOACE-0015A manufactured by Japan Fine Wax Co., Ltd.

[0117] • Zinc oxide: Three types of zinc oxide produced by Zhengtong Chemical Industry Co., Ltd.

[0118] • Stearic acid: Beads Stearic Acid manufactured by Nippon Oil Company

[0119] • Vulcanization accelerator-1: Nokucera-CZ-G manufactured by Ouchi Shinsei Chemical Co., Ltd.

[0120] • Vulcanization accelerator-2: Sumitomo Chemical Co., Ltd. ANKSINOL DG

[0121] • Sulfur: Kinka printing ink made by Tsurumi Chemical Industry Co., Ltd., containing micronized sulfur.

[0122] As shown in Table 1, the rubber compositions of Examples 1-3 were confirmed to have excellent wet grip, low rolling resistance, and cutting resistance.

[0123] The rubber composition of Comparative Example 1, which only incorporated unhydrogenated styrene resin instead of the aromatic modified terpene resin of Standard Example 1, actually deteriorated in terms of wet grip, low rolling resistance, and cut resistance.

[0124] The rubber composition of Comparative Example 2, which incorporates aromatic modified terpene resin and unhydrogenated styrene resin, actually deteriorates in wet grip, low rolling resistance, and cut resistance.

[0125] The rubber composition of Comparative Example 3 only used hydrogenated styrene resin instead of the aromatic modified terpene resin of Standard Example 1, resulting in deteriorated machinability.

[0126] As shown in Table 2, the rubber compositions of Examples 4 and 5, which are suitable for studless and studded tires, are confirmed to have excellent wet grip, low rolling resistance and cut resistance.

[0127] The rubber composition of Comparative Example 4, which only incorporated unhydrogenated styrene resin instead of the aromatic modified terpene resin of Standard Example 2, actually deteriorated in terms of wet grip, low rolling resistance, and cut resistance.

[0128] The rubber composition of Comparative Example 5, which incorporates aromatic modified terpene resin and unhydrogenated styrene resin, actually deteriorates in wet grip, low rolling resistance, and cut resistance.

[0129] The rubber composition of Comparative Example 6, which only incorporated hydrogenated styrene resin instead of the aromatic modified terpene resin of Standard Example 2, exhibited deteriorated machinability.

[0130] As shown in Table 3, the rubber compositions of Examples 6 and 7, which are suitable for winter tires, are confirmed to have excellent wet grip, low rolling resistance, and cut resistance.

[0131] The rubber composition of Comparative Example 7, which only incorporated unhydrogenated styrene resin instead of the aromatic modified terpene resin of Standard Example 3, actually deteriorated in terms of wet grip, low rolling resistance, and cut resistance.

[0132] The rubber composition of Comparative Example 8, which incorporates aromatic modified terpene resin and unhydrogenated styrene resin, actually deteriorates in wet grip, low rolling resistance, and cut resistance.

[0133] The rubber composition of Comparative Example 9, which only incorporated hydrogenated styrene resin instead of the aromatic modified terpene resin of Standard Example 3, exhibited deteriorated machinability.

[0134] As shown in Table 4, the rubber compositions of Examples 8 and 9, which are suitable for all-season tires, are confirmed to have excellent wet grip, low rolling resistance, and cut resistance.

[0135] The rubber composition of Comparative Example 10, which only incorporated unhydrogenated styrene resin instead of the aromatic modified terpene resin of Standard Example 4, actually deteriorated in terms of wet grip, low rolling resistance, and cut resistance.

[0136] The rubber composition of Comparative Example 11, which incorporates aromatic modified terpene resin and unhydrogenated styrene resin, actually deteriorates in wet grip, low rolling resistance, and cut resistance.

[0137] The rubber composition of Comparative Example 12, which only incorporated hydrogenated styrene resin instead of the aromatic modified terpene resin of Standard Example 4, exhibited deteriorated machinability.

[0138] As shown in Table 5, the rubber compositions of Examples 10 and 11, which are suitable for high-performance tires and racing tires, are confirmed to have excellent wet grip, low rolling resistance and cut resistance.

[0139] The rubber composition of Comparative Example 13, which only incorporated unhydrogenated styrene resin instead of the aromatic modified terpene resin of Standard Example 5, actually deteriorated in terms of wet grip, low rolling resistance, and cut resistance.

[0140] The rubber composition of Comparative Example 14, which incorporates aromatic modified terpene resin and unhydrogenated styrene resin, actually deteriorates in wet grip, low rolling resistance, and cut resistance.

[0141] The rubber composition of Comparative Example 15, which only incorporated hydrogenated styrene resin instead of the aromatic modified terpene resin of Standard Example 5, exhibited deteriorated machinability.

[0142] As shown in Table 6, the rubber compositions of Examples 12 and 13, which are suitable for low fuel consumption tires, are confirmed to have excellent wet grip, low rolling resistance, and cutting resistance.

[0143] The rubber composition of Comparative Example 16, which only incorporated unhydrogenated styrene resin instead of the aromatic modified terpene resin of Standard Example 6, actually deteriorated in terms of wet grip, low rolling resistance, and cut resistance.

[0144] The rubber composition of Comparative Example 17, which incorporates aromatic modified terpene resin and unhydrogenated styrene resin, actually deteriorates in wet grip, low rolling resistance, and cut resistance.

[0145] The rubber composition of Comparative Example 18, which only incorporated hydrogenated styrene resin instead of the aromatic modified terpene resin of Standard Example 6, exhibited deteriorated machinability.

Claims

1. A rubber composition, characterized in that, The mixture comprises 1-150 parts by weight of a mixed resin in 100 parts by weight of diene rubber, wherein the mixed resin contains 1-99% by weight of hydrogenated styrene resin and 99-1% by weight of aromatic modified terpene resin, wherein the hydrogenated styrene resin is a resin obtained by hydrogenating styrene resin formed from styrene monomer. The hydrogenation rate of the hydrogenated styrene resin is 40-90%.

2. The rubber composition according to claim 1, characterized in that, The diene rubber contains 5 to 300 parts by weight of inorganic filler.

3. The rubber composition according to claim 1 or 2, characterized in that, The diene-based rubber includes natural rubber and butadiene rubber, and the average glass transition temperature of the diene-based rubber is -100℃ to -80℃.

4. The rubber composition according to claim 1 or 2, characterized in that, 10 to 90 parts by mass of silica are incorporated into 100 parts by mass of the diene-based rubber.

5. The rubber composition according to claim 1 or 2, characterized in that, The diene-based rubber includes styrene-butadiene rubber and butadiene rubber, and the average glass transition temperature of the diene-based rubber is -100℃ to -50℃.

6. The rubber composition according to claim 1 or 2, characterized in that, The diene rubber contains 90 to 180 parts by mass of silica in 100 parts by mass.

7. The rubber composition according to claim 1 or 2, characterized in that, The diene-based rubber includes styrene-butadiene rubber, and the average glass transition temperature of the diene-based rubber is -80℃ to -20℃.

8. The rubber composition according to claim 7, characterized in that, 10 to 90 parts by mass of silica are incorporated into 100 parts by mass of the diene-based rubber.

9. The rubber composition according to claim 1 or 2, characterized in that, The diene-based rubber includes styrene-butadiene rubber, and the average glass transition temperature of the diene-based rubber is higher than -50°C and lower than -20°C.

10. The rubber composition according to claim 9, characterized in that, The diene rubber contains 90 to 180 parts by mass of silica in 100 parts by mass.

11. The rubber composition according to claim 1 or 2, characterized in that, The diene-based rubber includes styrene-butadiene rubber, and the average glass transition temperature of the diene-based rubber is -40℃ to -20℃.

12. The rubber composition according to claim 11, characterized in that, The diene rubber contains 10 or more but less than 90 parts by mass of silica in 100 parts by mass.

13. A tire made by forming the tread using any one of the rubber compositions claimed in claims 1 to 12.

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