JP2017095673A - tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tire having suppressed snow jamming and snow adhesion, especially a tire having suppressed snow jamming and snow adhesion while maintaining wet grip performance without depending on a tread pattern shape and excellent in on-ice performance and abrasion resistance.SOLUTION: There is provided a tire using a rubber composition containing a rubber component and a terpene-based resin and/or a cyclopentadiene-based resin and having contact angle of pure water of 125 to 140°.SELECTED DRAWING: None

Description

  The present invention relates to a tire manufactured using a predetermined rubber composition.

  Conventionally, as a method for improving the grip performance on snow and snow of winter tires such as studless tires and snow tires, by reducing the hardness (Hs) of the rubber composition for the tread, the elastic modulus (modulus) at low temperature is reduced ( (Improves low-temperature characteristics), improves adhesion friction, provides a specified sipe on the tread block surface, obtains grip on the snowy road surface, and provides deep lateral grooves on the tread surface. However, a method has been proposed in which a grip force is obtained by running so as to grab the compressed snow.

  The sipe provided on the block surface can exert a grip force by contacting with snow or ice on the road surface. However, when “with snow” occurs where snow adheres to the tread surface, the sipe cannot come into contact with snow or ice on the road surface, and there is a problem that the inherent grip performance on ice and snow cannot be exhibited.

  Further, the snow caught in the lateral groove is drained by the time when the tire makes a round and contacts the snow on the road surface again. Thereby, the lateral groove can exhibit a grip force repeatedly. However, if a “snow clog” occurs, which makes it impossible to remove snow, there is a problem that the lateral grooves cannot grip the snow, that is, the grip performance on the snow that is inherent cannot be exhibited.

  As a method for solving these problems, a method for forming a tread pattern such as a lateral groove into a predetermined shape has been proposed. For example, Patent Document 1 describes a method of suppressing snow attachment by making a tread pattern a predetermined shape. Patent Document 2 describes a method of suppressing snow clogging by designing a lateral groove into a predetermined shape.

JP 2008-221955 A JP 2014-80050 A

  There is a limit to the suppression of snow clogging and snowing by only the tread pattern shape such as a lateral groove, and further improvement of on-ice grip performance is required. In addition, tread pattern shapes such as lateral grooves are constrained to shapes that can prevent snow clogging and snowing, which reduces the degree of freedom in shape design, sacrificing performance on ice and snow, wear resistance, wet grip performance, etc. There is a problem of becoming.

  An object of the present invention is to provide a tire in which snow clogging and snow are suppressed. In particular, it is an object of the present invention to provide a tire excellent in performance on ice and snow, in which snow clogging and snow attachment are suppressed while maintaining wet grip performance and wear resistance without depending on the tread pattern shape.

  The present invention relates to a tire using a rubber composition containing a rubber component, a terpene resin and / or a cyclopentadiene resin and having a pure water contact angle of 125 to 140 °.

  The terpene resin is preferably a hydrogenated terpene resin.

  The cyclopentadiene resin is preferably a hydrogenated cyclopentadiene resin.

  According to the tire using the rubber composition of the present invention and a rubber composition containing a terpene resin and / or a cyclopentadiene resin and having a pure water contact angle of 125 to 140 °, snow clogging and snow attachment are suppressed. Tires can be provided.

  The tire of the present invention is characterized by using a rubber composition containing a rubber component and a terpene resin and / or a cyclopentadiene resin and having a contact angle with pure water within a predetermined range.

  It does not specifically limit as said rubber component, It can be set as the rubber component conventionally used as a rubber composition for tires. For example, at least one diene rubber component selected from the group consisting of natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR) and styrene butadiene rubber (SBR) can be used. Especially, it is preferable to contain NR and BR from the reason that it is excellent in a low temperature characteristic.

  The NR is not particularly limited, and those commonly used in the tire industry can be used. Examples thereof include SIR20, RSS # 3, and TSR20. Further, as the IR, those generally used in the tire industry can be used.

  The content when NR and / or IR is contained in the rubber component is preferably 10% by mass or more, and more preferably 20% by mass or more, from the viewpoint of excellent rubber kneading processability and extrusion processability. Further, the content of NR and / or IR is preferably 80% by mass or less, and more preferably 70% by mass or less from the viewpoint of excellent low-temperature characteristics.

  As the BR, various BR such as high-cis 1,4-polybutadiene rubber (high-cis BR), butadiene rubber containing 1,2-syndiotactic polybutadiene crystals (SPB-containing BR), modified butadiene rubber (modified BR), and the like are used. Can do.

  The high cis BR is a butadiene rubber having a cis 1,4 bond content of 90% by weight or more. Examples of such high-sis BR include BR1220 manufactured by Nippon Zeon Co., Ltd., BR130B manufactured by Ube Industries, Ltd., and BR150B. By containing the high cis BR, low temperature characteristics and wear resistance can be improved.

  Examples of the SPB-containing BR include those in which 1,2-syndiotactic polybutadiene crystals are not simply dispersed in BR but are dispersed after being chemically bonded to BR. Examples of such SPB-containing BR include VCR-303, VCR-412 and VCR-617 manufactured by Ube Industries.

  The modified BR is obtained by polymerizing 1,3-butadiene with a lithium initiator and then adding a tin compound. Further, the modified BR molecule has a terminal end bonded with a tin-carbon bond ( Tin-modified BR) and butadiene rubber (modified BR for silica) having a condensed alkoxysilane compound at the active terminal of the butadiene rubber. Examples of such modified BR include BR1250H (tin modified) manufactured by Nippon Zeon Co., Ltd., S modified polymer (modified for silica) manufactured by Sumitomo Chemical Co., Ltd., and the like.

  Among these various BRs, it is preferable to use a high-cis BR or a modified BR for silica from the viewpoint of excellent low-temperature characteristics and wear resistance.

  In the case where BR is contained in the rubber component, the content is preferably 20% by mass or more, and more preferably 30% by mass or more, from the viewpoint of low temperature characteristics and wear resistance. Moreover, 90 mass% or less is preferable from the point of preventing the deterioration of the workability of rubber | gum, and, as for content of the said various BR, 80 mass% or less is more preferable.

  Examples of the diene rubber component include acrylonitrile butadiene rubber (NBR), chloroprene rubber (CR), styrene isoprene butadiene rubber (SIBR), ethylene propylene diene rubber (EPDM) in addition to the NR, IR, BR and SBR. Among these, one or more can be selected and used together with NR and BR. However, these rubber components may not be included because the low-temperature characteristics are greatly reduced. preferable.

  In addition to the diene rubber component, the rubber component contains a rubber component such as butyl rubber (IIR), halogenated butyl rubber (X-IIR), and a halide of a copolymer of isomonoolefin and paraalkylstyrene. However, it is preferable not to include these rubber components because the low-temperature characteristics are greatly lowered.

  The rubber composition according to the present invention contains a terpene resin and / or a cyclopentadiene resin. By containing a terpene resin and / or a cyclopentadiene resin, the water repellency of the rubber composition is improved. By using the rubber composition as a tire, it is possible to obtain a tire in which snow clogging and snow attachment are suppressed. be able to.

  Terpene resins and cyclopentadiene resins are tire rubber compositions such as coumarone resins, petroleum resins (aliphatic petroleum resins, aromatic petroleum resins, alicyclic petroleum resins, etc.), phenolic resins, rosin derivatives, etc. The SP value is lower than that of other adhesive resins used in products. Here, the SP value means a solubility parameter calculated by the Hoy method on the basis of the structure of the compound, and the lower the SP value of the two compounds, the lower the compatibility. Here, since the SP value of water is about 23 and the SP value of the other adhesive resin is about 9 to 12, the terpene resin having a lower SP value than the other adhesive resins is more compatible with water. A water-repellent property of the rubber composition can be improved by forming a rubber composition containing an adhesive resin having low solubility. The Hoy method is a calculation method described in, for example, K. L. Hoy “Table of Solubility Parameters”, Solvent and Coatings Materials Research and Development Department, Union Carbites Corp. (1985).

  As the terpene resin, at least one polyterpene resin selected from terpene raw materials such as α-pinene, β-pinene, limonene, dipentene, etc., aromatic modified terpene resins using terpene compounds and aromatic compounds as raw materials, terpenes Terpene resins such as terpene phenol resin (terpene resin that has not been hydrogenated) made from compounds and phenolic compounds, and those that have been subjected to hydrogenation treatment (hydrogenated terpene resin) Resin). Here, as an aromatic compound used as the raw material of the aromatic modified terpene resin, for example, styrene, α-methylstyrene, vinyl toluene, divinyl toluene and the like can be mentioned, and as a phenol compound used as a raw material of the terpene phenol resin, Examples include phenol, bisphenol A, cresol, xylenol and the like.

  Among the terpene resins, hydrogenated terpene resins are preferable because the SP value is lower, the compatibility with the rubber component is better, and the water repellency can be further improved. A hydrogenated polyterpene resin is more preferred because it can be added and has excellent durability. The hydrogenation treatment to the terpene resin can be carried out by a known method. In the present invention, a commercially available hydrogenated terpene resin can also be used.

  The softening point of the terpene resin is preferably 75 ° C. or higher, more preferably 80 ° C. or higher, and further preferably 90 ° C. or higher from the viewpoint of ease of handling. Moreover, from a viewpoint of workability and the dispersibility improvement of a rubber component and a filler, 150 degrees C or less is preferable, 140 degrees C or less is more preferable, 130 degrees C or less is further more preferable. The softening point of the resin in the present invention is determined by using a flow tester (such as CFT-500D manufactured by Shimadzu Corporation) and using a plunger while heating 1 g of resin as a sample at a heating rate of 6 ° C./min. A load of 1.96 MPa was applied, the nozzle was extruded from a nozzle having a diameter of 1 mm and a length of 1 mm, and the plunger drop amount of the flow tester with respect to the temperature was plotted.

  The glass transition temperature (Tg) of the terpene-based resin is preferably 60 ° C. or lower, more preferably 50 ° C. or lower, because the glass transition temperature of the rubber composition is increased and durability is prevented from deteriorating. Further, the lower limit of the glass transition temperature of the terpene resin is not particularly limited, but is preferably 5 ° C. or higher because it can have a weight average molecular weight (Mw) equal to or higher than that of oil and can ensure hardly volatility. Further, the weight average molecular weight of the terpene resin is preferably 300 or less because it is excellent in volatility at high temperature and easily disappears.

  The SP value of the terpene resin is preferably 8.60 or less and more preferably 8.50 or less because the water repellency of the rubber composition can be further improved. The lower limit of the SP value of the terpene resin is preferably 7.5 or more from the viewpoint of compatibility with the rubber component.

  The softening point of the cyclopentadiene resin is preferably 80 ° C. or higher, more preferably 90 ° C. or higher, and further preferably 100 ° C. or higher, from the viewpoint of ease of handling. Moreover, from a viewpoint of workability and the dispersibility improvement of a rubber component and a filler, 160 degrees C or less is preferable, 150 degrees C or less is more preferable, 140 degrees C or less is further more preferable. The softening point of the resin in the present invention is determined by using a flow tester (such as CFT-500D manufactured by Shimadzu Corporation) and using a plunger while heating 1 g of resin as a sample at a heating rate of 6 ° C./min. A load of 1.96 MPa was applied, the nozzle was extruded from a nozzle having a diameter of 1 mm and a length of 1 mm, and the plunger drop amount of the flow tester with respect to the temperature was plotted.

  The glass transition temperature (Tg) of the cyclopentadiene resin is preferably 90 ° C. or less, and more preferably 80 ° C. or less, because the glass transition temperature of the rubber composition is increased to prevent the durability from deteriorating. In addition, the lower limit of the glass transition temperature of the cyclopentadiene resin is not particularly limited, but is preferably 30 ° C. or higher because it can have a weight average molecular weight (Mw) equal to or higher than that of oil and ensure low volatility. In addition, the weight average molecular weight of the cyclopentadiene resin is preferably 1000 or less because it is excellent in volatility at high temperature and easily disappears.

  The SP value of the cyclopentadiene resin is preferably 8.5 or less and more preferably 8.4 or less because the water repellency of the rubber composition can be further improved. The lower limit of the SP value of the cyclopentadiene resin is preferably 7.9 or more from the viewpoint of compatibility with the rubber component.

  The content of the terpene resin and / or cyclopentadiene resin with respect to 100 parts by mass of the rubber component is preferably 5 parts by mass or more, more preferably 8 parts by mass or more, from the reason that the effects of the present invention can be obtained satisfactorily. The above is more preferable. In addition, the content of the terpene resin and / or cyclopentadiene resin is preferably 40 parts by mass or less, more preferably 30 parts by mass or less from the viewpoint that the hardness, moldability, and viscosity of the rubber composition can be appropriately secured. preferable. In addition, when it contains a terpene resin and a cyclopentadiene resin, when it contains two or more terpene resins or a cyclopentadiene resin, the total content is the content of the terpene resin and / or cyclopentadiene resin. And

  In addition to the rubber component and the terpene-based resin and cyclopentadiene-based resin, the rubber composition according to the present invention includes compounding agents and additives conventionally used in the tire industry, such as various reinforcing fillers, coupling agents, and oxidizing agents. Zinc, various oils, softeners, waxes, various anti-aging agents, vulcanizing agents such as stearic acid and sulfur, various vulcanization accelerators and the like can be appropriately contained as necessary.

  The various reinforcing fillers can be arbitrarily selected from those conventionally used in tire rubber compositions, but carbon black and silica are mainly preferred.

  Examples of carbon black include furnace black, acetylene black, thermal black, channel black, graphite, and the like. These carbon blacks may be used alone or in combination of two or more. Among these, furnace black is preferable because it can improve the low temperature characteristics and wear performance in a well-balanced manner.

The nitrogen adsorption specific surface area (N ₂ SA) of carbon black is preferably 70 m ² / g or more, more preferably 90 m ² / g or more, from the viewpoint that sufficient reinforcement and wear resistance can be obtained. Also, N ₂ SA of carbon black is excellent in dispersibility, from the viewpoint that it is difficult to heat generation, preferably 300 meters ² / g or less, more preferably 250m ² / g. In this specification, N ₂ SA of carbon black is measured according to JIS K 6217-2 “Basic characteristics of carbon black for rubber—Part 2: Determination of specific surface area—Nitrogen adsorption method—Single point method” Value.

  In the case of containing carbon black, the content with respect to 100 parts by mass of the rubber component is preferably 3 parts by mass or more, and more preferably 4 parts by mass or more. When the amount is less than 3 parts by mass, sufficient reinforcing properties tend not to be obtained. The carbon black content is preferably 200 parts by mass or less, more preferably 150 parts by mass or less, and still more preferably 60 parts by mass or less. When it exceeds 200 mass parts, there exists a tendency for workability to deteriorate, the tendency to generate | occur | produce heat easily, and a tendency for abrasion resistance to fall.

  The silica is not particularly limited, and examples thereof include dry process silica (anhydrous silicic acid), wet process silica (hydrous silicic acid), and the like, but wet process silica is preferable because of its large number of silanol groups.

The nitrogen adsorption specific surface area (N ₂ SA) of silica is preferably 80 m ² / g or more, more preferably 100 m ² / g or more, from the viewpoint of durability and elongation at break. The N ₂ SA of the silica, from the viewpoint of fuel economy and workability, preferably 250 meters ² / g or less, more preferably 220 m ² / g. In this specification, N ₂ SA of silica is a value measured according to ASTM D3037-93.

  The content with respect to 100 parts by mass of the rubber component in the case of containing silica is preferably 5 parts by mass or more, more preferably 10 parts by mass or more from the viewpoint of durability and elongation at break. Further, the content of silica is 200 parts by mass from the viewpoint of improving dispersibility at the time of kneading, and suppressing reduction of workability due to re-aggregation of silica during heating during rolling and storage after rolling. The following is preferable, and 150 parts by mass or less is more preferable.

  When silica is contained, it is preferable to use a silane coupling agent in combination. As the silane coupling agent, any silane coupling agent conventionally used in combination with silica can be used in the rubber industry. For example, Si75, Si266 (bis (3-triethoxysilyl) manufactured by Evonik Degussa Co., Ltd. Propyl) disulfide), sulfides such as Si69 (bis (3-triethoxysilylpropyl) tetrasulfide) manufactured by the same company, 3-mercaptopropyltrimethoxysilane, NXT-Z100, NXT-Z45, NXT manufactured by Momentive, etc. Mercapto-based (silane coupling agent having a mercapto group), vinyl-based such as vinyltriethoxysilane, amino-based such as 3-aminopropyltriethoxysilane, glycidoxy-based such as γ-glycidoxypropyltriethoxysilane, 3- Nitropropi Nitro-based, such as trimethoxysilane, 3-chloropropyl-chloro system such as trimethoxysilane. These may be used alone or in combination of two or more. Of these, sulfide type and mercapto type are preferable from the viewpoints of strong bonding strength with silica and excellent low heat build-up.

  In the case of containing a silane coupling agent, the content with respect to 100 parts by mass of silica is preferably 2 parts by mass or more, and more preferably 3 parts by mass or more. When content of a silane coupling agent is less than 2 mass parts, there exists a tendency for the silica dispersibility improvement effect not to be fully acquired. Further, the content of the silane coupling agent is preferably 25 parts by mass or less, and more preferably 20 parts by mass or less. When content of a silane coupling agent exceeds 25 mass parts, there exists a tendency for the effect corresponding to cost not to be acquired.

  The rubber composition according to the present invention can be produced by a known method. For example, each of the above components can be produced by a method of kneading using a rubber kneader such as an open roll, a Banbury mixer, a closed kneader, and then vulcanizing.

  The rubber composition according to the present invention has a pure water contact angle of 125 to 140 °, preferably 128 to 140 °, and more preferably 130 to 140 ° or more. Here, the contact angle with pure water means that pure water is dropped into a small particle using a glass thin tube or the like on the surface of a rubber composition held horizontally, and the end of the droplet at that time is the rubber composition The angle between the surface and the surface. A larger contact angle indicates higher water repellency. The contact angle can be measured using a contact angle measuring device.

  The pneumatic tire of the present invention can be produced by a usual method using the rubber composition. That is, a non-vulcanized rubber composition obtained by kneading each of the components described above is extruded together with other tire members on a tire molding machine by extruding in accordance with the shape of the tire member. The tire of the present invention can be obtained by forming an unvulcanized tire by molding and heating and pressurizing the unvulcanized tire in a vulcanizer. Since the rubber composition is a rubber composition that can suppress snow clogging and snowing, it is preferably a rubber composition that constitutes a tread and / or sidewall on the outer periphery of the tire. It is more preferable to use a rubber composition that constitutes a tread that is more required to suppress sticking.

  The tire of the present invention is preferably a pneumatic tire. Particularly, a pneumatic tire having a tread composed of the rubber composition is a tire in which snow clogging and snowing are suppressed without depending on the tread pattern shape. Therefore, it is preferably applied to winter tires such as studless tires and snow tires, and more preferably applied to studless tires that require grip performance on ice.

  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.
NR: TSR20
BR: BR1220 (Non-modified BR, cis content: 96% by mass) manufactured by Nippon Zeon Co., Ltd.
Carbon Black: Dia Black I (ASTM No. N220, N ₂ SA: 114 m ² / g, DBP: 114 ml / 100 g) manufactured by Mitsubishi Chemical Corporation
Silica: Ultrasil VN3 manufactured by Evonik Degussa (N ₂ SA: 175 m ² / g, average primary particle size: 15 nm)
Terpene resin 1: PX1150N manufactured by Yashara Chemical Co., Ltd. (polyterpene resin not hydrogenated, softening point: 115 ° C.)
Terpene resin 2: P125 manufactured by Yashara Chemical Co., Ltd. (hydrogenated polyterpene resin, softening point: 125 ° C.)
Dicyclopentadiene resin 1: Opper PR-140 manufactured by ExxonMobil (hydrogenated dicyclopentadiene resin, softening point: 100 ° C.)
Dicyclopentadiene resin 2: Opper PR-120 manufactured by ExxonMobil (hydrogenated dicyclopentadiene resin, softening point: 120 ° C.)
Aromatic petroleum resin: SYLVARES SA85 manufactured by Arizona Chemical (copolymer of α-methylstyrene and styrene, softening point: 85 ° C., Mw: 1000)
Silane coupling agent: Si75 (bis (3-triethoxysilylpropyl) disulfide) manufactured by Evonik Degussa
Wax: Sunnock N manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.
Anti-aging agent: Antigen 6C (N- (1,3-dimethylbutyl) -N′-phenyl-p-phenylenediamine) manufactured by Sumitomo Chemical Co., Ltd.
Oil: Process X-140 (Aroma Oil) manufactured by Japan Energy Co., Ltd.
Stearic acid: Stearic acid “椿” manufactured by NOF Corporation
Zinc oxide: Zinc Hua No. 1 manufactured by Mitsui Mining & Smelting Co., Ltd. Sulfur: Powdered sulfur vulcanization accelerator manufactured by Karuizawa Sulfur Co., Ltd .: Noxeller CZ (N-cyclohexyl-2-made by Ouchi Shinsei Chemical Co., Ltd.) Benzothiazolylsulfenamide)

Examples and Comparative Examples According to the formulation shown in Table 1, using a 1.7 L closed Banbury mixer, kneading chemicals other than sulfur and vulcanization accelerator for 5 minutes until reaching 150 ° C. Obtained. Next, using an open roll, sulfur and a vulcanization accelerator were added to the obtained kneaded product, and kneaded for 3 minutes at 80 ° C. to obtain an unvulcanized rubber composition. Furthermore, the obtained unvulcanized rubber composition was press vulcanized for 12 minutes under the condition of 170 ° C. to obtain a rubber composition for each test.

  Further, the unvulcanized rubber composition is extruded into a tire tread shape by an extruder equipped with a predetermined-shaped die, and is bonded together with other tire members to form an unvulcanized tire. A test tire (size: 195 / 65R15, studless tire) was produced by press vulcanization for 12 minutes.

  The following evaluation was performed about the obtained unvulcanized rubber composition, the vulcanized rubber composition, and the test tire. The evaluation results are shown in Tables 1 and 2.

Contact angle of pure water When unvulcanized rubber composition is press vulcanized, polyimide film (Kapton manufactured by Toray DuPont Co., Ltd.) is pressed for the purpose of unifying the surface roughness of the vulcanized rubber composition. A rubber composition for water repellency measurement was produced in the same manner as the test rubber composition except that it was sandwiched between a vulcanizer and an unvulcanized rubber composition. Each water-repellent measurement rubber composition was measured by measuring the contact angle of the droplets with a contact angle measuring device (CA-A type machine manufactured by Kyowa Interface Science Co., Ltd.). Pure water was used as the droplet, and measurement was performed 5 seconds after the dropping. It shows that a vulcanized rubber composition is excellent in water repellency, so that a contact angle is large.

Abrasion resistance performance Each test tire was mounted on all wheels of a vehicle (domestic FF2000cc), the groove depth of the tire tread portion after a mileage of 8000 km was measured, and the mileage when the tire groove depth was reduced by 1 mm was obtained. . The results are expressed as an index, and the larger the index, the better the wear resistance. The index was calculated by the following formula. The reference example in Table 1 is Comparative Example 1, and the reference example in Table 2 is Comparative Example 2.
(Abrasion resistance index) = (travel distance when the tire groove of each blending example is reduced by 1 mm) / (travel distance when the tire groove of the reference example is reduced by 1 mm) × 100

Wet grip performance Each test tire was mounted on all wheels of a vehicle (domestic FF2000cc), and a braking distance from an initial speed of 100 km / h was determined on a wet asphalt road surface. The results are expressed as an index, and the larger the index, the better the wet grip property. The index was calculated by the following formula. The reference example in Table 1 is Comparative Example 1, and the reference example in Table 2 is Comparative Example 2.
(Wet grip index) = (braking distance of reference example) / (braking distance of each blending example) × 100

Performance on ice and snow The test tire was mounted on a domestic 2000cc FR vehicle, and the vehicle was actually run on ice and snow under the following conditions to evaluate the performance on ice and snow. Specifically, for the performance evaluation on ice and snow, the stop distance required to stop the vehicle by driving on the snow with the vehicle and stepping on the lock brake at a speed of 30 km / h (stop on ice and stop on snow) Was measured and expressed as an index according to the following formula. The larger the index, the better the performance on ice and snow (grip performance on ice and snow). If the index value exceeds 100, it can be said that the performance on ice and snow is improved. The reference example in Table 1 is Comparative Example 1, and the reference example in Table 2 is Comparative Example 2.
(Braking performance [performance on ice and snow] index) = (braking stop distance of reference example) / (braking stop distance of each formulation) × 100
(On ice) Test place: Hokkaido Nayoro Test Course, Temperature: -1 to -6 ° C
(Snow) Test place: Hokkaido Nayoro test course, Temperature: -2 to -10 ° C

Snow clogging and snowing Each test tire is mounted on an actual test vehicle (domestic FR car, displacement: 2000 cc), running on the snow, snow clogging and snowing in the lateral groove of each test tire after running It was observed visually and evaluated on a 5-point scale. The larger the score, the higher the effect of suppressing snow clogging and snowing, and it can be evaluated that snow clogging and snowing are suppressed if the score is 4 or more. The test place was the Hokkaido Nayoro Test Course of Sumitomo Rubber Industries, Ltd., and the snow temperature was −2 to −10 ° C.

  From the results of Tables 1 and 2, a tire having a tread composed of a rubber composition containing a rubber component, a terpene resin and / or a cyclopentadiene resin and having a pure water contact angle satisfying a predetermined range is obtained. Thus, it can be seen that, without depending on the tread pattern shape, while maintaining wet grip performance and wear resistance, snow clogging and snow attachment are suppressed, and a tire excellent in performance on ice and snow can be obtained.

Claims (3)

Containing a rubber component, a terpene resin and / or a cyclopentadiene resin,
A tire using a rubber composition having a pure water contact angle of 125 to 140 °. The tire according to claim 1, wherein the terpene resin is a hydrogenated terpene resin. The tire according to claim 1, wherein the cyclopentadiene resin is a hydrogenated cyclopentadiene resin.