JP6594611B2 - High performance tires - Google Patents

Description

  The present invention relates to a high-performance tire having a tread composed of a predetermined rubber composition.

  It is desired for a tread for a high-performance tire to maintain excellent handling stability (grip performance) on a dry road surface (dry road surface) from the initial driving to the end of driving. That is, it is desired to maintain good initial grip performance and good grip performance during traveling.

  Conventionally, in order to improve the initial grip performance, methods for increasing the amount of liquid polymer in the tread rubber composition and methods for blending a low-temperature softener have been studied. However, although the initial grip performance is improved by these methods, there is a problem that the grip performance during traveling decreases as the temperature of the tread rises. Moreover, since a double bond exists in a liquid polymer, there exists a problem that bridge | crosslinking becomes loose and abrasion resistance falls.

  On the other hand, for the purpose of obtaining stable grip performance during traveling, a method of blending an adhesive resin into a tread rubber composition has been studied. However, although a stable grip performance during traveling can be obtained by blending an adhesive resin, there is a problem that the initial grip performance is greatly reduced.

  Patent Document 1 includes a rubber component containing an amine / ketone-based anti-aging agent, a mixed resin obtained by mixing two or more resins, stearic acid, and zinc oxide, thereby providing good production load and anti-aging characteristics. While a tread rubber composition for high-performance tires that is excellent in grip performance, initial grip performance, wear resistance, and appearance characteristics has been described while ensuring, wear performance, which is an important performance of high-performance tires, during running There is still room for improvement in improving the grip performance and the initial grip performance.

JP 2014-105273 A

  An object of the present invention is to provide a high-performance tire capable of simultaneously improving the initial grip performance on a dry road surface and the stable grip performance during traveling at a high level while maintaining sufficient wear resistance.

  As a result of intensive studies, the inventors of the present invention have included a rubber composition containing a softener containing a predetermined amount of an adhesive resin and a predetermined amount of a low-temperature plasticizer, so that grip performance during running is maintained while maintaining wear resistance. It was found that the above-mentioned problem can be solved by greatly improving the initial grip performance while maintaining the effect of improving the present invention, and the present invention was completed through further studies.

  That is, the present invention is a high-performance tire having a tread composed of a rubber composition containing a rubber component and a softening agent, and the softening agent is an adhesive of 35 to 100 parts by mass with respect to 100 parts by mass of the rubber component. The present invention relates to a high-performance tire that is a softening agent including a resin and 10 to 50 parts by mass of a low-temperature plasticizer.

  It is preferable that the content of the adhesive resin in the softener is 25% by mass or more.

  The ratio of the content of the adhesive resin to the content of the low temperature plasticizer (content of adhesive resin / content of low temperature plasticizer) is preferably 1.0 to 3.0.

  The softening point of the adhesive resin is preferably 80 to 170 ° C.

  The adhesive resin is preferably at least one selected from the group consisting of phenolic resins, coumarone indene resins, terpene resins and acrylic resins.

  The freezing point of the low temperature plasticizer is preferably −50 ° C. or lower.

  The viscosity of the low temperature plasticizer at 25 ° C. is preferably 30 mPa · s or less.

  According to the present invention, a high performance tire having a tread composed of a rubber composition and a rubber composition containing a softener containing a predetermined amount of an adhesive resin and a predetermined amount of a low-temperature plasticizer is sufficient. It is possible to provide a high-performance tire that can improve the initial grip performance particularly on a dry road surface and the stable grip performance during traveling to a high level at the same time while maintaining wear resistance.

  The high-performance tire of the present invention is characterized by having a tread composed of a rubber composition and a rubber composition containing a softening agent including an adhesive resin and a low-temperature plasticizer.

  Examples of the rubber component include natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene butadiene rubber (SBR), styrene isoprene butadiene rubber (SIBR), ethylene propylene diene rubber (EPDM), and chloroprene. Examples thereof include diene rubbers such as rubber (CR), acrylonitrile butadiene rubber (NBR), and butyl rubber (IIR). These rubber components may be used alone or in combination of two or more. Of these, NR, BR, and SBR are preferable, and SBR is more preferable because grip performance and wear resistance can be obtained in a well-balanced manner. In addition, the rubber component in this specification is a rubber component mix | blended separately from the below-mentioned liquid diene polymer.

  The SBR is not particularly limited, and emulsion-polymerized styrene butadiene rubber (E-SBR), solution-polymerized styrene butadiene rubber (S-SBR), and modified SBRs modified at the ends of these SBRs (modified E-SBR, modified S-). Commonly used in the tire industry, such as SBR). Among these, S-SBR is preferable from the viewpoint of achieving both wear resistance and stable grip performance during traveling.

The styrene content of SBR is preferably 20% by mass or more, and more preferably 25% by mass or more. When the styrene content of SBR is less than 20% by mass, sufficient grip performance tends not to be obtained. Moreover, 60 mass% or less is preferable and, as for the styrene content of SBR, 50 mass% or less is more preferable. When the styrene content of SBR exceeds 60% by mass, not only the wear resistance decreases, but also the temperature dependency increases, the performance change with respect to the temperature change becomes large, and the stable grip performance during traveling is increased. There is a tendency not to be obtained well. In addition, the styrene content of SBR in the present specification is a value calculated by H ¹ -NMR measurement.

  The content of SBR in the rubber component in the case of containing SBR is preferably 10% by mass or more, more preferably 15% by mass or more, and further preferably 60% by mass or more. When the content of SBR is less than 10% by mass, sufficient heat resistance, grip performance, and wear resistance tend not to be obtained. Further, the upper limit of the SBR content is not particularly limited, and is most preferably 100% by mass from the viewpoint of achieving both wear resistance and stable grip performance during traveling.

  The softening agent is a softening agent containing an adhesive resin and a low-temperature plasticizer, and the initial grip performance and good running performance are improved by using the low-temperature plasticizer to improve the deterioration of the initial grip performance due to the blending of the adhesive resin. The grip performance can be improved at a high level at the same time.

  Examples of the adhesive resin include resins conventionally used in rubber compositions for tires such as aromatic petroleum resins. Examples of aromatic petroleum resins include phenolic resins, coumarone indene resins, terpene resins, styrene resins, acrylic resins, rosin resins, dicyclopentadiene resins (DCPD resins), and the like. Examples of the phenolic resin include colesin (manufactured by BASF) and tackolol (manufactured by Taoka Chemical Industry Co., Ltd.). Examples of the coumarone indene resin include Escron (manufactured by Nippon Steel Chemical Co., Ltd.), neopolymer (manufactured by JX Nippon Mining & Energy Corporation), and the like. Examples of the styrene resin include Sylvatrax 4401 (manufactured by Arizona chemical). Examples of the terpene resin include TR7125 (manufactured by Arizona chemical) and TO125 (manufactured by Yasuhara Chemical Co., Ltd.). These adhesive resins may be used alone or in combination of two or more. Especially, it is preferable to use a phenol-type resin, a coumarone indene resin, a terpene resin, and an acrylic resin because it has excellent grip performance during traveling.

  The adhesive resin is more preferably used in combination with a low softening point adhesive resin (low softening point resin) and a high softening point adhesive resin (high softening point resin). By blending a low softening point resin, the initial grip performance can be further improved, and by blending a high softening point resin, better grip performance during running can be obtained.

  The softening point of the low softening point resin is preferably 60 ° C. or higher, and more preferably 70 ° C. or higher. When the softening point is less than 60 ° C., there is a possibility that stable grip performance during traveling cannot be obtained. The softening point of the low softening point resin is preferably 115 ° C. or lower, and more preferably 110 ° C. or lower. When the softening point exceeds 115 ° C, the initial grip performance may be deteriorated.

  The low softening point resin is not particularly limited as long as the softening point is within the above range, but among them, a coumarone indene resin is preferable because a stable grip performance during running can be obtained.

  The softening point of the high softening point resin is preferably 120 ° C. or higher, and more preferably 140 ° C. or higher. When the softening point is less than 120 ° C., there is a possibility that stable grip performance during traveling cannot be obtained. The softening point of the high softening point resin is preferably 170 ° C. or lower, and more preferably 150 ° C. or lower. When the softening point exceeds 170 ° C., the initial grip performance may be deteriorated.

  The high softening point resin is not particularly limited as long as the softening point is within the above range, and among these, a terpene resin is preferable because it has an excellent balance with the initial grip performance.

  In this specification, the softening point of the low softening point resin and the high softening point resin is determined by measuring the softening point specified in JIS K 6220-1: 2001 with a ring and ball softening point measuring device, is there.

  Content with respect to 100 mass parts of rubber components of the said adhesive resin is 35 mass parts or more, 45 mass parts or more are preferable and 50 mass parts or more are more preferable. When the content of the adhesive resin is less than 35 parts by mass, there is a tendency that stable grip performance during traveling cannot be obtained. Further, the content of the adhesive resin is 100 parts by mass or less, preferably 90 parts by mass or less, and more preferably 80 parts by mass or less. When the content of the adhesive resin exceeds 100 parts by mass, the tackiness of the unvulcanized rubber composition tends to be high and the processability tends to deteriorate.

  Furthermore, the content of the adhesive resin is preferably 25% by mass or more, and more preferably 30% by mass or more in the softening agent, because good grip performance during traveling can be obtained. Moreover, although the upper limit of content of the adhesive resin in a softening agent is not specifically limited, From the relationship with content of a low temperature plasticizer, it is 75 mass% or less. The content of the adhesive resin in the softener is the content of the adhesive resin in the total content of the adhesive resin, the low temperature plasticizer, the oil and the liquid diene polymer contained in the rubber composition according to the present invention. Amount.

  Examples of the low-temperature plasticizer include dibutyl adipate (DBA), diisobutyl adipate (DIBA), dioctyl adipate (DOA), di-2-ethylhexyl azelate (DOZ), dibutyl sebacate (DBS), diisononyl adipate (DINA), diethyl phthalate (DEP), dioctyl phthalate (DOP), diundecyl phthalate (DUP), dibutyl phthalate (DBP), dioctyl sebacate (DOS), tributyl phosphate (TBP), trioctyl phosphate ( TOP), triethyl phosphate (TEP), trimethyl phosphate (TMP), thymidine triphosphate (TTP), tricresyl phosphate (TCP), ester plasticizers such as trixylenyl phosphate (TXP), and the like at low temperatures Plastic effect and wear resistant balun From, DOS, TOP is preferable.

  The freezing point of the low temperature plasticizer is preferably −50 ° C. or less, more preferably −70 ° C. or less, because a sufficient initial grip improving effect can be obtained. Moreover, the minimum of the freezing point of a low temperature plasticizer is not specifically limited.

  The viscosity of the low-temperature plasticizer at 25 ° C. is preferably 30 mPa · s or less, more preferably 20 mPa · s or less, because a sufficient initial grip improving effect can be obtained. Moreover, the minimum of the viscosity of a low temperature plasticizer is not specifically limited.

  Content with respect to 100 mass parts of rubber components of a low temperature plasticizer is 10 mass parts or more, 20 mass parts or more are preferable and 30 mass parts or more are more preferable. When the content of the low temperature plasticizer is less than 10 parts by mass, there is a tendency that sufficient initial grip performance cannot be obtained. Moreover, content of a low temperature plasticizer is 50 mass parts or less, 45 mass parts or less are preferable, and 40 mass parts or less are more preferable. When the content of the low temperature plasticizer exceeds 50 parts by mass, there is a tendency that stable grip performance during traveling cannot be obtained.

  Furthermore, the ratio of the content of the adhesive resin to the content of the low temperature plasticizer (adhesive resin content / low temperature plasticizer content) is preferably 1.0 or more, and more preferably 1.2 or more. If the content ratio is less than 1.0, sufficient grip performance during running may not be obtained. Further, the content ratio is preferably 3.0 or less, and more preferably 2.5 or less. If the content ratio exceeds 3.0, sufficient initial grip performance may not be obtained.

  The rubber composition according to the present invention may further contain oil (including a polymer oil fraction) or a liquid diene polymer as a softening agent in terms of initial grip performance, stable grip performance during traveling, and the like. To preferred.

  Examples of the oil include process oils such as paraffinic, aroma-based, and naphthenic process oils.

  The oil content relative to 100 parts by mass of the rubber component when oil is contained is preferably 15 parts by mass or more, and more preferably 30 parts by mass or more. When the oil content is less than 15 parts by mass, the effect of addition tends not to be obtained. Moreover, 85 mass parts or less are preferable, and, as for content of oil, 75 mass parts or less are more preferable. When the oil content exceeds 85 parts by mass, the wear resistance tends to deteriorate. The oil content in the present specification includes the oil contained in the oil-extended rubber.

  The liquid diene polymer is a diene polymer in a liquid state at room temperature (25 ° C.), for example, a liquid styrene butadiene copolymer (liquid SBR), a liquid butadiene polymer (liquid BR), or a liquid isoprene polymer. (Liquid IR), liquid styrene isoprene copolymer (liquid SIR), and the like. Among these, liquid SBR is preferable because it provides a good balance between wear resistance and stable grip performance during traveling.

The weight average molecular weight (Mw) of the liquid diene polymer is preferably 1.0 × 10 ³ or more, and more preferably 3.0 × 10 ³ or more. When the Mw of the liquid diene polymer is less than 1.0 × 10 ³ , the wear resistance and fracture characteristics are lowered, and sufficient durability tends not to be ensured. Further, the Mw of the liquid diene polymer is preferably 2.0 × 10 ⁵ or less, and more preferably 1.5 × 10 ⁴ or less. When the Mw of the liquid diene polymer exceeds 2.0 × 10 ⁵ , the viscosity of the polymerization solution becomes too high and the productivity tends to deteriorate. In addition, Mw of the liquid diene polymer in this specification is a polystyrene conversion value measured by gel permeation chromatography (GPC).

  When the liquid diene polymer is contained, the content of the liquid diene polymer with respect to 100 parts by mass of the rubber component is preferably 20 parts by mass or more, and more preferably 30 parts by mass or more. When the content of the liquid diene polymer is less than 20 parts by mass, sufficient grip performance tends not to be obtained. Further, the content of the liquid diene polymer is preferably 80 parts by mass or less, and more preferably 40 parts by mass or less. When the content of the liquid diene polymer exceeds 80 parts by mass, the wear resistance tends to deteriorate.

  The content of the softening agent (the total content of the adhesive resin, the low-temperature plasticizer, the oil, and the liquid diene polymer) is preferably 50 parts by mass or more and more preferably 100 parts by mass or more with respect to 100 parts by mass of the rubber component. Preferably, 120 parts by mass or more is more preferable. The softener content is preferably 250 parts by mass or less, more preferably 200 parts by mass or less, and still more preferably 180 parts by mass or less. When the content of the softening agent is within the above range, the effects of the present invention can be obtained more suitably.

  In addition to the components described above, the rubber composition according to the present invention includes a compounding agent conventionally used in the rubber industry, for example, a reinforcing filler such as carbon black, silica, calcium carbonate, alumina, clay, talc, wax, Zinc oxide, stearic acid, various anti-aging agents, vulcanizing agents, vulcanization accelerators and the like can be appropriately blended.

  The reinforcing filler preferably contains carbon black because of its excellent wear resistance. Examples of carbon black include carbon black produced by an oil furnace method, and two or more types having different colloidal characteristics may be used in combination. Specific examples include GPF, HAF, ISAF, and SAF. Among these, SAF is preferable.

Nitrogen adsorption specific surface area (N ₂ SA) of carbon black is preferably not less than 100 m ² / g, more preferably at least 105m ² / g, more 110m ² / g is more preferred. When N ₂ SA is less than 100 m ² / g, grip performance tends to decrease. Further, N ₂ SA of carbon black is preferably 600 m ² / g or less, more preferably 250 m ² / g or less, and further preferably 180 m ² / g or less. When N ₂ SA of carbon black exceeds 600 m ² / g, the dispersibility is inferior and the wear resistance tends to decrease. In this specification, N ₂ SA of carbon black is a value measured according to JIS K6217-2: 2001.

  The DBP oil absorption of carbon black is preferably 50 ml / 100 g or more, more preferably 100 ml / 100 g or more. When the DBP oil absorption is less than 50 ml / 100 g, there is a tendency that sufficient wear resistance cannot be obtained. The DBP oil absorption of carbon black is preferably 250 ml / 100 g or less, more preferably 200 ml / 100 g or less, and more preferably 135 ml / 100 g or less. When the DBP oil absorption exceeds 250 ml / 100 g, grip performance tends to decrease. In addition, the DBP oil absorption of carbon black in the present specification is a value measured according to JIS K6217-4: 2008.

  The content of carbon black with respect to 100 parts by mass of the rubber component in the case of containing carbon black is preferably 50 parts by mass or more, more preferably 80 parts by mass or more, and further preferably 100 parts by mass or more. When the content of carbon black is less than 50 parts by mass, sufficient wear resistance and grip performance tend not to be obtained. Also, the content of carbon black is preferably 200 parts by mass or less, and 150 parts by mass or less. Is more preferable. When content of carbon black exceeds 200 mass parts, there exists a tendency for grip performance to fall.

  The zinc oxide is not particularly limited as long as it is used in the rubber field such as a tire, but it is preferable to use fine zinc oxide.

  The average primary particle diameter of the fine particle zinc oxide is preferably 200 nm or less, and more preferably 100 nm or less. The lower limit of the average primary particle diameter of zinc oxide is not particularly limited, but is preferably 20 nm or more, and more preferably 30 nm or more. In addition, the average primary particle diameter of zinc oxide in this specification is an average particle diameter (average primary particle diameter) converted from a specific surface area measured by a BET method by nitrogen adsorption.

  In the case of containing zinc oxide, the content of zinc oxide with respect to 100 parts by mass of the rubber component is preferably 0.5 parts by mass or more, and more preferably 1 part by mass or more. Moreover, 10 mass parts or less are preferable and, as for content of zinc oxide, 5 mass parts or less are more preferable. When the content of zinc oxide is within the above range, the effects of the present invention can be more suitably obtained.

  Examples of the vulcanization accelerator include sulfenamide, thiazole, thiuram, and guanidine vulcanization accelerators, and thiazole and thiuram vulcanization accelerators can be preferably used. Examples of thiazole-based vulcanization accelerators include 2-mercaptobenzothiazole, cyclohexylamine salt of 2-mercaptobenzothiazole, di-2-benzothiazolyl disulfide, and the like. Among them, di-2-benzothia Zolyl disulfide is preferred. Examples of the thiuram-based vulcanization accelerator include tetramethylthiuram disulfide (TMTD), tetrabenzylthiuram disulfide (TBzTD), tetrakis (2-ethylhexyl) thiuram disulfide (TOT-N), and among others, TOT- N is preferred.

  The content of the vulcanization accelerator with respect to 100 parts by mass of the rubber component in the case of containing the vulcanization accelerator is preferably 1 part by mass or more, and more preferably 3 parts by mass or more. When the content of the vulcanization accelerator is less than 1 part by mass, a sufficient vulcanization speed cannot be obtained, and there is a tendency that good grip performance and wear resistance cannot be obtained. Moreover, 15 mass parts or less are preferable, and, as for content of a vulcanization accelerator, 10 mass parts or less are more preferable. When the content of the vulcanization accelerator exceeds 15 parts by mass, blooming tends to occur, and the grip performance and wear resistance tend to decrease.

  As a method for producing the rubber composition according to the present invention, a known method can be used. For example, the rubber composition can be produced by a method of kneading each component with a Banbury mixer, a kneader, an open roll, etc., and then vulcanizing. .

  The high-performance tire of the present invention can be produced by a usual method using the rubber composition according to the present invention. That is, a rubber composition containing the above-mentioned compounding agent as necessary with respect to the rubber component is extruded in accordance with the shape of the tread at an unvulcanized stage, and is pasted together with other tire members on a tire molding machine. In addition, the high-performance tire of the present invention can be manufactured by forming an unvulcanized tire by molding by an ordinary method and heating and pressurizing the unvulcanized tire in a vulcanizer. In addition, the high performance tire in the present invention can be suitably applied to a racing tire such as a race, particularly a high performance dry tire used on a dry road surface.

  The present invention will be described based on examples, but the present invention is not limited to the examples.

Hereinafter, various chemicals used in Examples and Comparative Examples are shown together.
SBR: Toughden 4850 manufactured by Asahi Kasei Co., Ltd. (S-SBR, styrene content: 40% by mass, containing 50 parts by mass of oil with respect to 100 parts by mass of rubber solid content)
Carbon black: N219 manufactured by Cabot Japan Co., Ltd. (N ₂ SA: 106 m ² / g, DBP oil absorption: 78 ml / 100 g)
Oil: Diana Process AH-24 manufactured by Idemitsu Kosan Co., Ltd.
Liquid diene polymer: L-SBR-820 manufactured by Kuraray Co., Ltd. (liquid SBR, Mw: 10,000)
Adhesive resin 1: Coumarone G-90 (Coumarone indene resin (low softening point resin), manufactured by Nikkiso Chemical Co., Ltd., softening point: 90 ° C.)
Adhesive resin 2: TO125 manufactured by Yasuhara Chemical Co., Ltd. (terpene resin (high softening point resin), softening point 125 ° C.)
Adhesive resin 3: Nisseki Neopolymer 170S manufactured by JX Nippon Oil & Energy Corporation (coumarone indene resin (high softening point resin), softening point: 160 ° C.)
Adhesive resin 4: Sylvatrax 4401 manufactured by Arizona Chemical Co. (styrene resin (low softening point resin), softening point: 85 ° C.)
Low temperature plasticizer 1: DOS manufactured by Daihachi Chemical Industry Co., Ltd. (freezing point: -62 ° C, viscosity: 18 mPa · s (25 ° C))
Low temperature plasticizer 2: TOP manufactured by Daihachi Chemical Industry Co., Ltd. (Freezing point: -70 ° C or lower, viscosity: 12 mPa · s (25 ° C))
Zinc oxide: Zincock Super F-1 (average primary particle size: 100 nm) manufactured by Hakusui Tech Co., Ltd.
Wax: Sunnock N manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.
Anti-aging agent 1: NOCRACK 6C (N- (1,3-dimethylbutyl) -N-phenyl-p-phenylenediamine, 6PPD) manufactured by Ouchi Shinsei Chemical Co., Ltd.
Anti-aging agent 2: NOCRACK RD (poly (2,2,4-trimethyl-1,2-dihydroquinoline)) manufactured by Ouchi Shinsei Chemical Co., Ltd.
Stearic acid: Stearic acid “椿” manufactured by NOF Corporation
Sulfur: Powder sulfur vulcanization accelerator manufactured by Tsurumi Chemical Co., Ltd. 1: Noxeller DM (di-2-benzothiazolyl disulfide) manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.
Vulcanization accelerator 2: Noxeller TOT-N (tetrakis (2-ethylhexyl) thiuram disulfide) manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.

Examples and Comparative Examples According to the contents shown in Tables 1 and 2, the above-mentioned various chemicals (excluding sulfur and vulcanization accelerator) were kneaded for 20 minutes at a discharge temperature of 140 ° C. in a 1.7 L Banbury mixer, and mixed. A kneaded paste was obtained. Sulfur and a vulcanization accelerator were added to the obtained kneaded product, and kneaded using an open roll to obtain an unvulcanized rubber composition. The obtained unvulcanized rubber composition was molded into a tread shape, and bonded together with other tire members on a tire molding machine, and vulcanized at 150 ° C. for 30 minutes to give a test tire (tire size: 215 / 45R17). The following evaluation was performed about the obtained tire for a test. The results are shown in Table 1.

<Initial grip performance>
The test tires were mounted on all the wheels of a domestic FR car (2000cc), and 10 laps were run on a dry asphalt road test course. At that time, the test driver evaluated the stability of the control at the time of steering in the second lap, and an index was displayed with Comparative Example 1 being 100. The larger the value, the higher the initial grip performance. Note that the initial grip performance index is 110 or more as the performance target index.

<Grip performance while driving>
The test tires were mounted on all the wheels of a domestic FR car (2000cc), and 10 laps were run on a dry asphalt road test course. At that time, the test driver compared and evaluated the stability of control during steering of the best lap and the final lap. The larger the value, the smaller the decrease in grip performance during traveling on a dry road surface, indicating that a stable grip performance during traveling can be obtained better. The grip performance index during traveling is set to 110 or more as a performance target index.

<Abrasion resistance>
The test tires were mounted on all the wheels of a domestic FR vehicle (2000 cc) and the vehicle was run on a dry asphalt road test course. The remaining groove amount of the tire tread rubber at that time was measured (15 mm when new), and the index was displayed with the remaining groove amount of Comparative Example 1 being 100. The larger the wear resistance index, the higher the wear resistance. Note that the wear resistance index is 96 or more as a performance target index.

  From the results of Tables 1 and 2, the high-performance tire having a tread composed of a rubber composition and a softening agent containing a predetermined amount of a pressure-sensitive adhesive resin and a predetermined amount of a low-temperature plasticizer has a sufficient resistance. It can be seen that the initial grip performance especially on the dry road surface and the stable grip performance during traveling can be improved at a high level at the same time while maintaining the wearability.

Claims (6)

A rubber composition containing a solution-polymerized styrene-butadiene rubber and / or a modified styrene-butadiene rubber and a softening agent (however, the softening point is -50 ° C to 50 ° C with respect to 100 parts by mass of the rubber component, and the vinyl bond content) And a composition containing 5 parts by mass or more of 50% or more high vinyl butadiene and a composition containing 10 parts by mass or more of a phenolic resin having a softening point of 110 to 150 ° C. and an OH value of 180 or more) High performance tire with tread
The softener, relative to 100 parts by mass of the rubber component, Ri softeners der containing 35 to 100 parts by weight of the adhesive resin, 10 to 50 parts by weight low plasticizer and 15 to 85 parts by weight of oil,
A high-performance tire having a ratio of the content of the adhesive resin to the content of the low-temperature plasticizer (content of the adhesive resin / content of the low-temperature plasticizer) of 1.2 to 3.0 . The high-performance tire according to claim 1, wherein the content of the adhesive resin in the softener is 25% by mass or more. The high-performance tire according to claim 1 or 2 , wherein the adhesive resin has a softening point of 80 to 170 ° C. The high-performance tire according to any one of claims 1 to 3 , wherein the adhesive resin is at least one selected from the group consisting of phenolic resins, coumarone indene resins, terpene resins, and acrylic resins. The high-performance tire according to any one of claims 1 to 4 , wherein a freezing point of the low-temperature plasticizer is -50 ° C or lower. The high-performance tire according to any one of claims 1 to 5 , wherein the low-temperature plasticizer has a viscosity at 25 ° C of 30 mPa · s or less.