Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C3/00—Tyres characterised by the transverse section
  • B60C3/04—Tyres characterised by the transverse section characterised by the relative dimensions of the section, e.g. low profile
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C1/00—Tyres characterised by the chemical composition or the physical arrangement or mixture of the composition
  • B60C1/0016—Compositions of the tread
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
  • B60C11/0041—Tyre tread bands; Tread patterns; Anti-skid inserts comprising different tread rubber layers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
  • B60C11/0041—Tyre tread bands; Tread patterns; Anti-skid inserts comprising different tread rubber layers
  • B60C11/005—Tyre tread bands; Tread patterns; Anti-skid inserts comprising different tread rubber layers with cap and base layers
  • B60C11/0058—Tyre tread bands; Tread patterns; Anti-skid inserts comprising different tread rubber layers with cap and base layers with different cap rubber layers in the axial direction
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
  • B60C11/03—Tread patterns
  • B60C11/0327—Tread patterns characterised by special properties of the tread pattern
  • B60C11/033—Tread patterns characterised by special properties of the tread pattern by the void or net-to-gross ratios of the patterns
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
  • B60C11/0008—Tyre tread bands; Tread patterns; Anti-skid inserts characterised by the tread rubber
  • B60C2011/0016—Physical properties or dimensions
  • B60C2011/0033—Thickness of the tread
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
  • B60C11/03—Tread patterns
  • B60C2011/0337—Tread patterns characterised by particular design features of the pattern
  • B60C2011/0339—Grooves
  • B60C2011/0341—Circumferential grooves
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
  • B60C11/03—Tread patterns
  • B60C2011/0337—Tread patterns characterised by particular design features of the pattern
  • B60C2011/0339—Grooves
  • B60C2011/0358—Lateral grooves, i.e. having an angle of 45 to 90 degees to the equatorial plane
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C2200/00—Tyres specially adapted for particular applications
  • B60C2200/04—Tyres specially adapted for particular applications for road vehicles, e.g. passenger cars
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/80—Technologies aiming to reduce greenhouse gasses emissions common to all road transportation technologies
  • Y02T10/86—Optimisation of rolling resistance, e.g. weight reduction 

Definitions

• the present invention relates to a pneumatic tire.
• the fuel efficiency of a tire can be evaluated by rolling resistance, and it is known that the smaller the rolling resistance, the better the fuel efficiency of the tire.
• Patent Documents 1 to 4 it has been proposed to reduce the rolling resistance by devising the shape of the tire and the composition of the rubber composition constituting the tread portion of the tire.
• Japanese Unexamined Patent Publication No. 2018-178034 Japanese Unexamined Patent Publication No. 2019-089911 WO2018 / 186637A Japanese Unexamined Patent Publication No. 2019-206643
• the present invention provides a pneumatic tire in which the grip performance at high speed running and the durability performance are sufficiently improved, and the grip performance at high speed running and the excellent durability performance can be exhibited. Is the subject.
• the present inventor has diligently studied the solution to the above problem, found that the above problem can be solved by the invention described below, and has completed the present invention.
• the invention according to claim 1 is Pneumatic tire with tread
• the tread portion has a ground contact surface formed of at least two types of rubber compositions having different thermal conductivitys. Furthermore, when the tire is incorporated into a regular rim, the cross-sectional width of the tire is Wt (mm), the outer diameter is Dt (mm), and the volume of the space occupied by the tire is the virtual volume V (mm 3 ) when the internal pressure is 250 kPa. , A pneumatic tire characterized by satisfying the following (formula 1) and (formula 2).
• the invention according to claim 2 is The pneumatic tire according to claim 1, wherein the tire satisfies the following (formula 3). 1718 ⁇ (Dt 2 x ⁇ / 4) / Wt ⁇ 2827.4 ... (Equation 3)
• the invention according to claim 3 is The pneumatic tire according to claim 1 or 2, wherein the tire satisfies the following (formula 4). [(V + 2.0 ⁇ 10 7 ) / Wt] ⁇ 2.88 ⁇ 10 5. (Equation 4)
• the invention according to claim 4 is The pneumatic tire according to claim 3, wherein the tire satisfies the following (formula 5). [(V + 2.5 ⁇ 10 7 ) / Wt] ⁇ 2.88 ⁇ 10 5. (Equation 5)
• the invention according to claim 5 is When the tire is built into a regular rim and the internal pressure is 250 kPa, the outer diameter of the tire is Dt (mm), and the cross-sectional height of the tire is Ht (mm), (Dt-2 x Ht) is 470 (mm) or more.
• the invention according to claim 6 is The pneumatic tire according to any one of claims 1 to 5, wherein the flatness is 40% or more.
• the invention according to claim 7 is The pneumatic tire according to claim 6, wherein the flatness is 45% or more.
• the invention according to claim 8 is The pneumatic tire according to claim 7, wherein the flatness is 47.5% or more.
• the invention according to claim 9 is The pneumatic tire according to claim 8, wherein the flatness is 50.0% or more.
• the invention according to claim 10 is Of the at least two types of rubber compositions having different thermal conductivitys, the thermal conductivity of the rubber composition having the highest thermal conductivity is Ka (W / m ⁇ K), and the heat of the rubber composition having the lowest thermal conductivity is Ka (W / m ⁇ K).
• Ka-Kb 0.01 ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ (Equation 6)
• the invention according to claim 11 is The pneumatic tire according to claim 10, wherein the tire satisfies the following (formula 7).
• the invention according to claim 12 is Of the at least two types of rubber compositions having different thermal conductivitys, the thermal conductivity of the rubber composition having the highest thermal conductivity is Ka (W / m ⁇ K), and the heat of the rubber composition having the lowest thermal conductivity is Ka (W / m ⁇ K).
• Ka W / m ⁇ K
• Ka Ka (W / m ⁇ K)
• the rubber composition having a thermal conductivity of Kb is compared with the ratio Sa (%) of the ground contact area of the ground contact portion formed from the rubber composition having a thermal conductivity of Ka to the total ground contact area.
• the ratio Sb (%) of the ground contact area of the ground contact portion formed from an object to the total ground contact area is large.
• the invention according to claim 13 is (Sb—Sa) ⁇ Wt ⁇ 2.50 ⁇ 10 4
• the invention according to claim 14 is Of the at least two types of rubber compositions having different thermal conductivitys, the loss measured under the conditions of the rubber composition having the lowest thermal conductivity at 30 ° C., frequency 10 Hz, initial strain 5%, and kinetic strain rate 1%.
• the invention according to claim 15 The pneumatic tire according to claim 14, wherein the 30 ° C. tan ⁇ is 0.14 or less.
• the invention according to claim 16 is The pneumatic tire according to any one of claims 1 to 15, wherein when the thickness of the tread portion is Td (mm), the following (formula 8) is satisfied. 30 °C tan ⁇ ⁇ Td ⁇ 1.5 ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ (Equation 8)
• the invention according to claim 17 is The pneumatic tire according to claim 16, wherein the tire satisfies the following (formula 9). 30 °C tan ⁇ ⁇ Td ⁇ 1.8 ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ (Equation 9)
• the invention according to claim 18 is A plurality of circumferential grooves extending continuously in the tire circumferential direction are formed in the tread portion.
• the invention according to claim 19 A plurality of lateral grooves extending in the tire axial direction are formed in the tread portion.
• the invention according to claim 20 One of claims 1 to 19, wherein the Dt is less than 685 (mm) when the outer diameter of the tire is Dt (mm) when the tire is incorporated in a regular rim and the internal pressure is 250 kPa.
• the invention according to claim 22 The pneumatic tire according to claim 21, wherein the cross-sectional width Wt (mm) is less than 200 mm.
• the invention according to claim 23 The pneumatic tire according to any one of claims 1 to 22, wherein the tire is a pneumatic tire for a passenger car.
• the present invention it is possible to provide a pneumatic tire in which the grip performance and durability performance at high speed running are sufficiently improved, and excellent grip performance at high speed running and excellent durability performance can be exhibited. Can be done.
• the tire according to the present invention is characterized in that the ground contact surface is formed of at least two types of rubber compositions having different thermal conductivitys.
• the tire according to the present invention is further incorporated in a regular rim, the cross-sectional width of the tire is Wt (mm) and the outer diameter is Dt (mm) when the internal pressure is 250 kPa, and the volume of the space occupied by the tire is virtual. It is also characterized by satisfying the following (Equation 1) and (Equation 2) when the volume is V (mm 3 ). 1700 ⁇ (Dt 2 ⁇ ⁇ / 4) / Wt ⁇ 2827.4 ⁇ ⁇ (Equation 1) [(V + 1.5 ⁇ 10 7 ) / Wt] ⁇ 2.88 ⁇ 10 5 ⁇ ⁇ (Equation 2)
• the ground plane is formed by at least two types of rubber compositions having different thermal conductivitys
• the tread surface is formed by each rubber composition over the entire circumference of the ground plane of the tread portion. It does not refer only to the case where the tread surface is formed, and the tread surface due to each rubber composition may be formed somewhere around the entire circumference. However, it is preferable that it is the entire circumference.
• the "contact patch” refers to the contact patch of the tread part when a maximum load capacity or a load close to it is applied to a tire that is built into a regular rim and has an internal pressure of 250 kPa.
• the "regular rim” is a rim defined for each tire in the standard system including the standard on which the tire is based.
• JATTA Japanese Automobile Tire Association
• JATTA YEAR BOOK If it is a standard rim in the applicable size described in, ETRTO (The European Tire and Rim Technical Organization), "Measuring Rim” described in “STANDARDS MANUAL”, TRA (The Tire, Inc.) If there is, it means “Design Rim” described in "YEAR BOOK”.
• the rim can be assembled and the internal pressure can be maintained, that is, the rim that does not cause air leakage between the rim and the tire has the smallest rim diameter, followed by the rim. Refers to the one with the narrowest width.
• the outer diameter Dt of the tire is the outer diameter of the tire in a state where the tire is assembled to the regular rim and the internal pressure is 250 kPa to make no load
• the cross-sectional width Wt of the tire is the tire assembled to the regular rim.
• the pattern and characters on the side of the tire were removed from the straight line distance (total width of the tire) between the sidewalls including all the patterns and characters on the side of the tire. The width.
• the virtual volume V (mm 3 ) of the tire is, specifically, the outer diameter Dt (mm) of the tire in the state where the tire is assembled to the regular rim and the internal pressure is 250 kPa and no load is applied.
• Cross-sectional height (distance from the bottom surface of the bead to the outermost surface of the tread, 1/2 the difference between the tire outer diameter and the nominal rim diameter) Ht (mm), based on the tire cross-sectional width Wt (mm) Can be calculated by the following formula.
• V [(Dt / 2) 2 - ⁇ (Dt / 2) -Ht ⁇ 2 ] ⁇ ⁇ ⁇ Wt
• Mechanism of effect manifestation in the tire according to the present invention The mechanism of effect manifestation in the tire according to the present invention, that is, the mechanism in which the grip performance and durability performance at high speed are sufficiently exhibited is presumed as follows. ..
• the cross-sectional width Wt (mm) and the outer diameter Dt (mm) of the tire satisfy 1700 ⁇ (Dt 2 ⁇ ⁇ / 4) / Wt ⁇ 2827.4 (Equation 1). I try to do it.
• (Dt 2 ⁇ ⁇ / 4) / Wt is preferably 1718 ⁇ (Dt 2 ⁇ ⁇ / 4) / Wt ⁇ 2827.4 (Equation 3).
• (Dt 2 ⁇ ⁇ / 4) / Wt is more preferably 1865 or more, further preferably 1963.5 or more, and further preferably 2018 or more.
• (Dt 2 ⁇ ⁇ / 4) / Wt is more preferably 1728 or more, further preferably 1731 or more, further preferably 1745 or more, and further preferably 1747 or more. It is preferable that it is 1751 or more, more preferably 1753 or more, further preferably 1763 or more, further preferably 1805 or more, further preferably 1811 or more, still more preferably 1829 or more. 1833 or more is further preferable, 1860 or more is further preferable, 2004 or more is further preferable, 2019 or more is further preferable, 2021 or more is further preferable, 2039 or more is further preferable, and 2131 or more. Is more preferable.
• the virtual volume V (mm 3 ) and the cross-sectional width Wt (mm) of the tire are further set to [(V + 1.5 ⁇ 10 7 ) / Wt] ⁇ 2.88 ⁇ 10 5 (Equation 2). I am trying to be satisfied.
• [( V + 1.5 ⁇ 107 ) / Wt] is more preferably 2.87 ⁇ 105 or less, further preferably 2.85 ⁇ 105 or less, and 2.80 ⁇ 105 or less. It is more preferably 2.59 ⁇ 105 or less, further preferably 2.55 ⁇ 105 or less, further preferably 2.54 ⁇ 105 or less, and 2.51 ⁇ 10 5 or less . It is more preferably less than or equal to 2.48 ⁇ 105 or less, further preferably 2.41 ⁇ 105 or less, still more preferably 2.25 ⁇ 105 or less, and 2.23 ⁇ .
• the ground contact surface of the tread portion is formed by at least two types of rubber compositions having different thermal conductivitys. As a result, heat flows in the tread portion, and it is considered that the deformation of the entire tread can be suppressed.
• the above-mentioned [( V + 2.0 ⁇ 10 7 ) / Wt] is more preferably 2.81 ⁇ 105 or less, further preferably 2.80 ⁇ 105 or less, and 2.79 ⁇ 105 . It is more preferably 2.75 ⁇ 105 or less, further preferably 2.63 ⁇ 105 or less, still more preferably 2.48 ⁇ 105 or less, and 2.47 ⁇ . It is more preferably 105 or less, further preferably 2.46 ⁇ 105 or less, further preferably 2.45 ⁇ 105 or less, and even more preferably 2.44 ⁇ 105 or less. It is more preferably 43 ⁇ 105 or less.
• [( V + 2.5 ⁇ 10 7 ) / Wt] is more preferably 2.85 ⁇ 105 or less, further preferably 2.77 ⁇ 105 or less, and 2.75 ⁇ 105 or less. It is more preferably 2.73 ⁇ 105 or less, further preferably 2.71 ⁇ 105 or less, further preferably 2.69 ⁇ 105 or less, and 2.68 ⁇ 105 or less. It is more preferably less than or equal to 2.67 ⁇ 105 or less.
• the tire according to the present invention preferably has a flatness of 40% or more.
• the area of the side portion can be increased, so that the heat release property of the entire tire can be further improved, the decrease in rigidity in the tread portion and the side portion can be suppressed, and the grip performance at high speeds can be deteriorated. Can be further suppressed.
• the flatness (%) described above can be obtained by the following formula using the cross-sectional height Ht (mm) and the cross-sectional width Wt (mm) of the tire when the internal pressure is 250 kPa. (Ht / Wt) x 100 (%)
• the above-mentioned flattening ratio is more preferably 44% or more, further preferably 45% or more, further preferably 47.5% or more, further preferably 48% or more, still more preferably 49% or more. It is more preferably 50% or more, further preferably 52.5% or more, further preferably 53% or more, further preferably 55% or more, further preferably 58% or more. It is preferably 59% or more, and more preferably 59% or more. There is no particular upper limit, but for example, it is 100% or less.
• the thermal conductivity of the rubber composition having the highest thermal conductivity is Ka (W / m ⁇ K), and the rubber composition having the lowest thermal conductivity.
• the thermal conductivity in the above is Kb (W / m ⁇ K)
• the larger (Ka—Kb) is, the larger the heat flow is generated on the ground surface of the tread portion, and the heat dissipation can be improved, which is preferable.
• Ka-Kb> 0.01 is preferable
• Ka-Kb ⁇ 0.02 is more preferable
• Ka-Kb> 0.05 is more preferable
• Ka-Kb it is more preferably .08, further preferably Ka-Kb> 0.10, even more preferably Ka-Kb ⁇ 0.11, and even more preferably Ka-Kb ⁇ 0.24.
• the upper limit of (Ka-Kb) is not particularly specified, but is preferably about 0.80.
• the specific Ka is preferably 0.3 to 0.9 W / m ⁇ K, and the Kb is preferably 0.1 to 0.7 W / m ⁇ K.
• the thermal conductivity K (W / m ⁇ K) is a value measured according to the hot wire method specified in JIS R 2616 (measurement temperature: 23 ° C.), and specifically, Kyoto Electronics Manufacturing Co., Ltd. It can be measured by using a rapid thermal conductivity meter such as "kemtherm QTM-500” manufactured by Resuka Co., Ltd. or a thermal conductivity measuring device such as "TCM1001” manufactured by Resuka Co., Ltd.
• the thermal conductivity can be adjusted by adjusting the blending ratio of carbon black, silica, etc. among the blending materials described later. It can also be adjusted by newly blending graphene, graphite, carbon nanofibers and the like.
• the shoulder region of the tread may be formed of a rubber composition having the highest thermal conductivity Ka, but considering efficient heat dissipation by grounding, the center region of the tread may be formed of a rubber composition having a thermal conductivity Ka. It is preferable to form the tire wider with an object, and it is preferable to form the tire wider as the width of the tire becomes wider.
• the ratio of the ground contact area of the ground contact portion formed from the rubber composition having the highest thermal conductivity Ka to the total ground contact area is Sa (%)
• the ground contact area is formed from the rubber composition having the lowest thermal conductivity Kb.
• Sb-Sa is more preferably 88% or more, further preferably 90% or more, further preferably 92% or more, still more preferably 94% or more.
• (Sb-Sa) ⁇ Wt ⁇ 2.00 ⁇ 10 4 is more preferable, and (Sb-Sa) ⁇ Wt ⁇ 1.89 ⁇ 10 4 is more preferable, and (Sb-Sa) ⁇ Wt ⁇ . It is more preferably 1.88 ⁇ 10 4 , further preferably (Sb—Sa) ⁇ Wt ⁇ 1.85 ⁇ 10 4 , and further preferably (Sb—Sa) ⁇ Wt ⁇ 1.80 ⁇ 10 4 .
• the rubber composition having the lowest thermal conductivity has a temperature of 30 ° C., a frequency of 10 Hz, an initial strain of 5%, and a dynamic strain rate of 1%.
• the loss positive contact (30 ° C. tan ⁇ ) measured under the conditions is, for example, preferably 0.1 or more and 0.7 or less, and more preferably 0.16 or less.
• the heat generation at the tread portion can be reduced and the temperature rise of the tire can be suppressed. It is possible to prevent damage to the tire and increase the durability by suppressing the decrease in the durability of the composition itself and the growth of the outer diameter due to the temperature rise. It is more preferable that it is 0.14 or less.
• the above-mentioned measurement of 30 ° C. tan ⁇ is performed on the rubber cut out from the radial outside of at least the groove bottom of the tire, preferably from the radial outside of the half depth of the deepest circumferential groove. Specifically, for example, it can be measured using a viscoelasticity measuring device of "Iplexer (registered trademark)" manufactured by GABO.
• the thickness of the tread portion is Td (mm) (Equation 8) is satisfied, and 30 ° C. tan ⁇ ⁇ Td ⁇ 1.8 (Equation 9) is satisfied. Then, it is more preferable, and it is further preferable that 30 ° C. tan ⁇ ⁇ Td ⁇ 2.0. By satisfying such an equation, the effect of the present invention can be more fully exhibited.
• the thickness Td of the tread portion is the distance (mm) from the outermost surface of the tread center portion to the cord layer, and specifically, for example, 4 mm or more and 25 mm or less.
• the tire according to the present invention has a circumferential groove in the tread portion that extends continuously in the tire circumferential direction, and the circumferential groove with respect to the groove width L 0 of the circumferential groove on the ground contact surface of the tread portion.
• the ratio of the tread width L 80 (L 80 / L 0 ) at a depth of 80% of the maximum depth is preferably 0.3 to 0.7.
• It is more preferably 0.35 to 0.65, further preferably 0.40 to 0.60, and particularly preferably 0.45 to 0.55.
• L 0 and L 80 are the linear distance (L 0 ) of the groove end portion on the tread surface portion of the tread circumferential groove of the tire, which is mounted on the regular rim and has an internal pressure of 250 kPa and is in a no-load state, and the groove. It refers to the minimum distance (L 80 ) of the groove wall at a depth of 80%.
• the rim width is between the bead parts of the section where the tire is cut out in the radial direction with a width of 2 to 4 cm. It can be obtained by pressing them together.
• a plurality of circumferential grooves are formed in the tread portion, and it is preferable that the total cross-sectional area of the plurality of circumferential grooves is 10 to 30% of the cross-sectional area of the tread portion. It is considered that this can suppress the movement of the tread portion and suppress the chipping of the tread portion. It is more preferably 15 to 27%, further preferably 18 to 25%, and particularly preferably 21 to 23%.
• the circumferential groove may be a groove that extends continuously in the circumferential direction, and a non-linear groove such as a zigzag shape or a wavy shape is also included in the circumferential groove.
• the cross-sectional area of the above-mentioned circumferential groove is the area composed of a straight line connecting the ends of the tread circumferential groove and a groove wall in a tire mounted on a regular rim and having an internal pressure of 250 kPa and in a no-load state. It refers to the total value of, and can be simply obtained by pressing the bead portion of the section cut out in the radial direction of the tire with a width of 2 to 4 cm according to the rim width.
• a plurality of lateral grooves extending in the tire axial direction are formed in the tread portion, and it is preferable that the total volume of the plurality of lateral grooves is 2.0 to 5.0% of the volume of the tread portion. .. It is considered that this can suppress the movement of the tread portion and suppress the chipping of the tread portion. It is more preferably 2.2 to 4.0%, further preferably 2.5 to 3.5%, and particularly preferably 2.7 to 3.0%.
• the volume of the lateral groove described above refers to the total volume of the volume composed of the surface connecting the ends of the lateral groove and the groove wall in a tire mounted on a regular rim and having an internal pressure of 250 kPa and in a no-load state. To put it simply, calculate the volume of each lateral groove and multiply it by the number of grooves, with the bead portion of the section cut out in the radial direction with a width of 2 to 4 cm pressed down according to the rim width. Can be found at. Further, the volume of the tread portion can be calculated by calculating the area of the portion of the tread portion not including the lateral groove from the section and multiplying it by the outer diameter, and obtaining the difference from the volume of the lateral groove. ..
• the ratio (Gw / Gd) of the groove width Gw to the groove depth Gd is 0.50 to 0.80 in these lateral grooves. It is preferable that a certain lateral groove is included, 0.53 to 0.77 is more preferable, 0.55 to 0.75 is more preferable, and 0.60 to 0.70 is particularly preferable.
• the groove width and groove depth of the lateral groove described above are the straight lines connecting the tread surface ends of the lateral grooves, which are perpendicular to the groove direction and are the maximum in the tire with an internal pressure of 250 kPa and no load. , And the maximum depth of the lateral groove, and can be simply calculated from the state where the bead portion of the section where the tire is cut out in the radial direction with a width of 2 to 4 cm is pressed according to the rim width. ..
• the specific outer diameter Dt (mm) is preferably, for example, 515 mm or more, and more preferably 558 mm or more. It is preferable that it is 585 mm or more, more preferably 650 mm or more, further preferably 658 mm or more, further preferably 663 mm or more, further preferably 664 mm or more, still more preferably 665 mm or more. It is more preferably 672 mm or more, and most preferably 673 mm or more.
• it is preferably less than 843 mm, more preferably 735 mm or less, further preferably less than 725 mm, further preferably 718 mm or less, further preferably 717 mm or less, still more preferably 716 mm or less. It is more preferably 713 mm or less, further preferably 709 mm or less, further preferably less than 707 mm, further preferably 693 mm or less, further preferably 690 mm or less, further preferably less than 685 mm, still more preferably 684 mm or less. It is more preferably 679 mm or less, further preferably 678 mm or less, and most preferably 674 mm or less.
• the specific cross-sectional width Wt (mm) is, for example, preferably 115 mm or more, more preferably 130 mm or more, further preferably 150 mm or more, still more preferably 170 mm or more, and even more preferably 175 mm.
• the above is even more preferable, 176 mm or more is even more preferable, 177 mm or more is even more preferable, 181 mm or more is even more preferable, 182 mm or more is even more preferable, and 185 mm or more is particularly preferable. It is preferably 193 mm or more, and most preferably 193 mm or more.
• it is preferably less than 305 mm, more preferably less than 245 mm, further preferably 232 mm or less, further preferably 231 mm or less, further preferably 230 mm or less, still more preferably 229 mm or less. It is more preferably 226 mm or less, further preferably less than 210 mm, further preferably less than 205 mm, further preferably 201 mm or less, further preferably 200 mm or less, still more preferably less than 200 mm, and even more preferably 199 mm or less. Is most preferable.
• the specific cross-sectional height Ht (mm) is, for example, preferably 37 mm or more, more preferably 69 mm or more, further preferably 70 mm or more, further preferably 71 mm or more, and further preferably 77 mm.
• the above is more preferable, 78 mm or more is further preferable, 79 mm or more is further preferable, 80 mm or more is further preferable, 81 mm or more is further preferable, 87 mm or more is further preferable, and 91 mm or more is 91 mm or more. It is more preferably 95 mm or more, further preferably 97 mm or more, further preferably 98 mm or more, still more preferably 99 mm or more.
• it is preferably less than 180 mm, more preferably 116 mm or less, further preferably 114 mm or less, further preferably less than 112 mm, further preferably 106 mm or less, still more preferably less than 101 mm. It is more preferably 100 mm or less.
• the specific virtual volume V is, for example, preferably 13,000,000 mm 3 or more, more preferably 23,225,099 mm 3 or more, and further preferably 23,279,803 mm 3 or more. It is preferable that it is 23,332,669 mm 3 or more, more preferably 28,653,292 mm 3 or more, more preferably 28,719,183 mm 3 or more, and 28,783,303 mm 3 or more. More preferably, 29,000,000 mm 3 or more, further preferably 29,988,186 mm 3 or more, more preferably 30,346,008 mm 3 or more, 34,384,955 mm 3 or more.
• it is preferably less than 66,000,000 mm3, more preferably 51,413,226 mm3 or less, further preferably less than 44,000,000 mm3, and 43,419,514 mm3 or less. More preferably, it is more preferably 42,160,723 mm 3 or less, further preferably 40,613,053 mm 3 or less, and further preferably less than 38,800,000 mm 3 .
• (Dt-2 ⁇ Ht) is preferably 450 (mm) or more, more preferably 456 (mm) or more, and 458. It is more preferably (mm) or more, further preferably 470 (mm) or more, further preferably 480 (mm) or more, further preferably 481 (mm) or more, and 482 (mm) or more. And even more preferable.
• the tread portion it is preferably less than 560 (mm), more preferably 559 (mm) or less, still more preferably 556 (mm) or less, and 534 (mm) or less. More preferably, it is more preferably 531 (mm) or less, further preferably less than 530 (mm), further preferably 510 (mm) or less, still more preferably less than 510 (mm), and 509 ( It is more preferably mm) or less, further preferably 507 (mm) or less, and further preferably 506 (mm) or less.
• the rubber composition that forms the tread portion of the tire according to the present invention has various compounding materials such as rubber components, fillers, softeners, vulcanizers, and vulcanization accelerators described below. It can be obtained by appropriately adjusting the amount, particularly the filler and the softening agent.
• the rubber component includes rubber generally used for manufacturing tires, such as butadiene rubber (BR), styrene-butadiene rubber (SBR), isoprene-based rubber, and nitrile rubber (NBR).
• BR butadiene rubber
• SBR styrene-butadiene rubber
• NBR nitrile rubber
• Polymer can be used, but among these, isoprene-based rubber, butadiene rubber (BR) and styrene-butadiene rubber (SBR) are preferably used.
• the content (total content) of isoprene-based rubber in 100 parts by mass of the rubber component is preferably 25 parts by mass or more, more preferably 35 parts by mass or more, and 45 parts by mass or more. Is more preferable. On the other hand, it is preferably 75 parts by mass or less, more preferably 65 parts by mass or less, and further preferably 55 parts by mass or less.
• isoprene-based rubber examples include natural rubber (NR), isoprene rubber (IR), modified NR, modified NR, modified IR, etc., but NR is preferable from the viewpoint of excellent strength.
• NR for example, SIR20, RSS # 3, TSR20, etc., which are common in the tire industry, can be used.
• the IR is not particularly limited, and for example, an IR 2200 or the like, which is common in the tire industry, can be used.
• Modified NR includes deproteinized natural rubber (DPNR), high-purity natural rubber (UPNR), etc.
• modified NR includes epoxidized natural rubber (ENR), hydrogenated natural rubber (HNR), grafted natural rubber, etc.
• Examples of the modified IR include epoxidized isoprene rubber, hydrogenated isoprene rubber, grafted isoprene rubber, and the like. These may be used alone or in combination of two or more.
• (B) BR The content of BR in 100 parts by mass of the rubber component is preferably 20 parts by mass or more, more preferably 30 parts by mass or more, and further preferably 35 parts by mass or more. On the other hand, it is preferably 60 parts by mass or less, more preferably 50 parts by mass or less, and further preferably 45 parts by mass or less.
• the weight average molecular weight of BR is, for example, more than 100,000 and less than 2 million.
• the vinyl bond amount of BR is, for example, more than 1% by mass and less than 30% by mass.
• the cis content of BR is, for example, more than 1% by mass and less than 98% by mass.
• the amount of trance of BR is, for example, more than 1% by mass and less than 60% by mass.
• the cis content can be measured by infrared absorption spectrum analysis.
• the BR is not particularly limited, and BR having a high cis content (cis content of 90% or more), BR having a low cis content, BR containing syndiotactic polybutadiene crystals, and the like can be used.
• the BR may be either a non-modified BR or a modified BR, and as the modified BR, for example, a BR modified with a compound (modifying agent) represented by the following formula can be used.
• R 1 , R 2 and R 3 are the same or different, and contain an alkyl group, an alkoxy group, a silyloxy group, an acetal group, a carboxyl group (-COOH), a mercapto group (-SH) or a derivative thereof.
• R 4 and R 5 represent the same or different hydrogen atoms or alkyl groups. R 4 and R 5 may be combined to form a ring structure with nitrogen atoms.
• n represents an integer.
• modified BR modified by the compound (modifying agent) represented by the above formula a BR having a polymerization terminal (active end) modified by the compound represented by the above formula can be used.
• Alkoxy groups are suitable for R 1 , R 2 and R 3 (preferably an alkoxy group having 1 to 8 carbon atoms, and more preferably an alkoxy group having 1 to 4 carbon atoms).
• Alkyl groups (preferably alkyl groups having 1 to 3 carbon atoms) are suitable as R 4 and R 5 .
• n is preferably 1 to 5, more preferably 2 to 4, and even more preferably 3.
• R 4 and R 5 are bonded to form a ring structure together with a nitrogen atom, a 4- to 8-membered ring is preferable.
• the alkoxy group also includes a cycloalkoxy group (cyclohexyloxy group, etc.) and an aryloxy group (phenoxy group, benzyloxy group, etc.).
• the above modifier include 2-dimethylaminoethyltrimethoxysilane, 3-dimethylaminopropyltrimethoxysilane, 2-dimethylaminoethyltriethoxysilane, 3-dimethylaminopropyltriethoxysilane, and 2-diethylaminoethyltri.
• Examples thereof include methoxysilane, 3-diethylaminopropyltrimethoxysilane, 2-diethylaminoethyltriethoxysilane, 3-diethylaminopropyltriethoxysilane and the like. These may be used alone or in combination of two or more.
• a modified BR modified with the following compound (modifying agent) can also be used.
• the modifier include polyglycidyl ethers of polyhydric alcohols such as ethylene glycol diglycidyl ether, glycerin triglycidyl ether, trimethylolethanetriglycidyl ether, and trimethylolpropane triglycidyl ether; and two or more diglycidylated bisphenol A and the like.
• Tetraglycidylaminodiphenylmethane tetraglycidyl-p-phenylenediamine, diglycidylaminomethylcyclohexane, tetraglycidyl-1,3-bisaminomethylcyclohexane and other diglycidylamino compounds; bis- (1-methylpropyl) carbamate chloride, Amino group-containing acid chlorides such as 4-morpholincarbonyl chloride, 1-pyrrolidincarbonyl chloride, N, N-dimethylcarbamide acid chloride, N, N-diethylcarbamide acid chloride; 1,3-bis- (glycidyloxypropyl) -tetra Epoxy group-containing silane compounds such as methyldisiloxane, (3-glycidyloxypropyl) -pentamethyldisiloxane; (trimethylsilyl) [3- (trimethoxysilyl) propyl] sulfide, (trimethyl
• silane compound Containing silane compound; N-substituted aziridine compound such as ethyleneimine and propyleneimine; methyltrietoki Sisilane, N, N-bis (trimethylsilyl) -3-aminopropyltrimethoxysilane, N, N-bis (trimethylsilyl) -3-aminopropyltriethoxysilane, N, N-bis (trimethylsilyl) aminoethyltrimethoxysilane, Alkoxysilanes such as N, N-bis (trimethylsilyl) aminoethyltriethoxysilane; 4-N, N-dimethylaminobenzophenone, 4-N, N-di-t-butylaminobenzophenone, 4-N, N-diphenylamino Benzophenone, 4,4'-bis (dimethylamino) benzophenone, 4,4'-bis (diethylamino) benzophenone, 4,4
• Benzaldehyde compounds having an amino group and / or a substituted amino group such as benzaldehyde; N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, N-phenyl-2-pyrrolidone, Nt-butyl-2-pyrrolidone, N-substituted pyroridone such as N-methyl-5-methyl-2-pyrrolidone N-substituted piperidone such as N-methyl-2-piperidone, N-vinyl-2-piperidone, N-phenyl-2-piperidone; N-methyl - ⁇ -caprolactam, N-phenyl- ⁇ -caprolactam, N-methyl- ⁇ -laurilolactum, N-vinyl- ⁇ -laurilolactum, N-methyl- ⁇ -propiolactam, N-phenyl- ⁇ -pro N-substituted lactams such as piolactam; in addition, N, N
• BR for example, products such as Ube Industries, Ltd., JSR Corporation, Asahi Kasei Corporation, and Nippon Zeon Corporation can be used.
• (C) SBR The content of SBR in 100 parts by mass of the rubber component is preferably 5 parts by mass or more, and more preferably 8 parts by mass or more. On the other hand, it is preferably 20 parts by mass or less, and more preferably 15 parts by mass or less.
• the weight average molecular weight of SBR is, for example, more than 100,000 and less than 2 million.
• the styrene content of SBR is 5% by mass or more, particularly 8% by mass or more. Further, less than 35% by mass is preferable, less than 25% by mass is more preferable, and less than 15% by mass is further preferable.
• the vinyl bond amount (1,2-bonded butadiene unit amount) of SBR is, for example, more than 5% by mass and less than 70% by mass.
• the structure identification of SBR (measurement of styrene content and vinyl bond amount) can be performed using, for example, an apparatus of the JNM-ECA series manufactured by JEOL Ltd.
• the SBR is not particularly limited, and for example, emulsion-polymerized styrene-butadiene rubber (E-SBR), solution-polymerized styrene-butadiene rubber (S-SBR), and the like can be used.
• E-SBR emulsion-polymerized styrene-butadiene rubber
• S-SBR solution-polymerized styrene-butadiene rubber
• the SBR may be either a non-modified SBR or a modified SBR, and these may be used alone or in combination of two or more.
• the modified SBR may be any SBR having a functional group that interacts with a filler such as silica.
• a filler such as silica
• at least one end of the SBR is modified with a compound having the above functional group (modifying agent).
• SBR end-modified SBR having the above functional group at the end
• main chain-modified SBR having the above-mentioned functional group in the main chain and main chain-end-modified SBR having the above-mentioned functional group at the main chain and the end (for example, to the main chain)
• SBR for example, SBR manufactured and sold by Sumitomo Chemical Co., Ltd., JSR Corporation, Asahi Kasei Co., Ltd., Nippon Zeon Co., Ltd., etc. can be used.
• the SBR may be used alone or in combination of two or more.
• rubber (polymer) generally used for producing tires such as nitrile rubber (NBR) may be contained.
• NBR nitrile rubber
• the rubber composition preferably contains a filler.
• the filler include silica, carbon black, calcium carbonate, talc, alumina, clay, aluminum hydroxide, mica and the like, and among these, silica and carbon black can be preferably used as the reinforcing agent. .. When silica is used, it is preferable to use it in combination with a silane coupling agent.
• the rubber composition preferably contains silica as a filling reinforcing agent.
• the BET specific surface area of silica is preferably more than 140 m 2 / g, more preferably more than 160 m 2 / g, from the viewpoint of obtaining good durability performance. On the other hand, from the viewpoint of obtaining good rolling resistance during high-speed running, it is preferably less than 250 m 2 / g, and more preferably less than 220 m 2 / g.
• the above-mentioned BET specific surface area is the value of N 2 SA measured by the BET method according to ASTM D3037-93.
• the content of silica with respect to 100 parts by mass of the rubber component is preferably more than 35 parts by mass, more preferably more than 40 parts by mass. On the other hand, 200 parts by mass or less is preferable, 100 parts by mass or less is more preferable, and 60 parts by mass or less is further preferable.
• silica examples include dry silica (anhydrous silica) and wet silica (hydrous silica). Of these, wet silica is preferable because it has a large number of silanol groups.
• silica for example, products such as Evonik, Degussa, Rhodia, Tosoh Silica Co., Ltd., Solvay Japan Co., Ltd., and Tokuyama Corporation can be used.
• the rubber composition preferably contains a silane coupling agent together with silica.
• the silane coupling agent is not particularly limited, and for example, bis (3-triethoxysilylpropyl) tetrasulfide, bis (2-triethoxysilylethyl) tetrasulfide, bis (4-triethoxysilylbutyl) tetrasulfide, and the like.
• silane coupling agent for example, products such as Degussa, Momentive, Shinetsu Silicone Co., Ltd., Tokyo Chemical Industry Co., Ltd., Azumax Co., Ltd., Toray Dow Corning Co., Ltd. can be used.
• the content of the silane coupling agent is, for example, more than 3 parts by mass and less than 25 parts by mass with respect to 100 parts by mass of silica.
• Carbon black The rubber composition preferably contains carbon black.
• the content of carbon black is, for example, more than 1 part by mass and less than 200 parts by mass with respect to 100 parts by mass of the rubber component.
• the carbon black is not particularly limited, and furnace black (furness carbon black) such as SAF, ISAF, HAF, MAF, FEF, SRF, GPF, APF, FF, CF, SCF and ECF; acetylene black (acetylene carbon black).
• furnace black furness carbon black
• thermal black thermal carbon black
• FT and MT channel black
• EPC EPC
• MPC MPC
• CC channel carbon black
• the nitrogen adsorption specific surface area (N 2 SA) of carbon black is, for example, more than 30 m 2 / g and less than 250 m 2 / g.
• the amount of dibutyl phthalate (DBP) absorbed by carbon black is, for example, more than 50 ml / 100 g and less than 250 ml / 100 g.
• the nitrogen adsorption specific surface area of carbon black is measured according to ASTM D4820-93, and the amount of DBP absorbed is measured according to ASTM D2414-93.
• Specific carbon black is not particularly limited, and examples thereof include N134, N110, N220, N234, N219, N339, N330, N326, N351, N550, and N762.
• Commercially available products include, for example, Asahi Carbon Co., Ltd., Cabot Japan Co., Ltd., Tokai Carbon Co., Ltd., Mitsubishi Chemical Corporation, Lion Corporation, Shin Nikka Carbon Co., Ltd., Columbia Carbon Co., Ltd., etc. Can be used. These may be used alone or in combination of two or more.
• the rubber composition is commonly used in the tire industry, for example, calcium carbonate, talc, alumina, clay, aluminum hydroxide, mica. Etc. may be further contained. Further, it is also preferable to use the above-mentioned graphene, graphite, carbon nanofibers or the like as a filler for adjusting the thermal conductivity of the rubber composition. These contents are, for example, more than 0.1 part by mass and less than 200 parts by mass with respect to 100 parts by mass of the rubber component.
• the rubber composition may contain oil (including spreading oil), liquid rubber, or the like as a softener.
• oil including spreading oil
• the total content of these is, for example, more than 1 part by mass, more preferably more than 8 parts by mass, still more preferably more than 10 parts by mass, based on 100 parts by mass of the rubber component. Further, less than 100 parts by mass is preferable, less than 40 parts by mass is more preferable, and less than 30 parts by mass is further preferable.
• the oil content also includes the amount of oil contained in rubber (oil spread rubber).
• oils examples include mineral oil (generally referred to as process oil), vegetable oil and fat, or a mixture thereof.
• process oil for example, paraffin-based process oil, aroma-based process oil, naphthen-based process oil and the like can be used.
• Vegetable oils and fats include castor oil, cottonseed oil, sesame oil, rapeseed oil, soybean oil, palm oil, palm oil, peanut oil, rosin, pine oil, pineapple, tall oil, corn oil, rice oil, beni flower oil, and sesame oil. Examples thereof include olive oil, sunflower oil, palm kernel oil, camellia oil, jojoba oil, macadamia nut oil, and tung oil.
• Specific process oils include, for example, Idemitsu Kosan Co., Ltd., Sankyo Yuka Kogyo Co., Ltd., Japan Energy Co., Ltd., Orisoi Co., Ltd., H & R Co., Ltd., Toyokuni Oil Co., Ltd., Showa Shell Sekiyu Co., Ltd. ( Products such as Co., Ltd. and Fuji Kosan Co., Ltd. can be used.
• the liquid rubber mentioned as the softener is a polymer in a liquid state at room temperature (25 ° C.) and a polymer having a monomer similar to that of solid rubber as a component.
• the liquid rubber include farnesene-based polymers, liquid diene-based polymers, and hydrogenated additives thereof.
• the farnesene-based polymer is a polymer obtained by polymerizing farnesene and has a structural unit based on farnesene.
• Farnesene includes ⁇ -farnesene ((3E, 7E) -3,7,11-trimethyl-1,3,6,10-dodecatetraene) and ⁇ -farnesene (7,11-dimethyl-3-methylene-1). , 6,10-dodecatorien) and other isomers are present.
• the farnesene-based polymer may be a farnesene homopolymer (farnesene homopolymer) or a copolymer of farnesene and a vinyl monomer (farnesene-vinyl monomer copolymer).
• liquid diene polymer examples include a liquid styrene-butadiene polymer (liquid SBR), a liquid butadiene polymer (liquid BR), a liquid isoprene polymer (liquid IR), and a liquid styrene isoprene copolymer (liquid SIR). Be done.
• liquid SBR liquid styrene-butadiene polymer
• liquid BR liquid butadiene polymer
• liquid IR liquid isoprene polymer
• liquid SIR liquid styrene isoprene copolymer
• the polystyrene-equivalent weight average molecular weight (Mw) of the liquid diene polymer measured by gel permeation chromatography (GPC) is, for example, more than 1.0 ⁇ 10 3 and less than 2.0 ⁇ 105 .
• Mw of the liquid diene polymer is a polystyrene-equivalent value measured by gel permeation chromatography (GPC).
• the content of the liquid rubber (total content of the liquid farnesene polymer, the liquid diene polymer, etc.) is, for example, more than 1 part by mass and less than 100 parts by mass with respect to 100 parts by mass of the rubber component.
• liquid rubber for example, products such as Kuraray Co., Ltd. and Clay Valley Co., Ltd. can be used.
• the rubber composition preferably contains a resin component, if necessary.
• the resin component may be solid or liquid at room temperature, and specific resin components include styrene resin, kumaron resin, terpene resin, C5 resin, C9 resin, C5C9 resin, and acrylic resin. Examples include resins such as resins, and two or more of them may be used in combination.
• the content of the resin component is, for example, more than 2 parts by mass, preferably less than 45 parts by mass, and more preferably less than 30 parts by mass with respect to 100 parts by mass of the rubber component.
• the styrene-based resin is a polymer using a styrene-based monomer as a constituent monomer, and examples thereof include a polymer obtained by polymerizing a styrene-based monomer as a main component (50% by mass or more).
• styrene-based monomers styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, ⁇ -methylstyrene, p-methoxystyrene, p-tert-butylstyrene, p-phenylstyrene, o-Chlorostyrene, m-chlorostyrene, p-chlorostyrene, etc.
• styrene-based monomers are individually polymerized, and in addition to copolymers obtained by copolymerizing two or more styrene-based monomers, styrene-based monomers And other monomer copolymers that can be copolymerized with this.
• Examples of the other monomers include acrylonitriles such as acrylonitrile and methacrylate, unsaturated carboxylic acids such as acrylics and methacrylic acid, unsaturated carboxylic acid esters such as methyl acrylate and methyl methacrylate, chloroprene and butadiene.
• Examples thereof include dienes such as isoprene, olefins such as 1-butane and 1-pentene; ⁇ , ⁇ -unsaturated carboxylic acids such as maleic anhydride or acid anhydrides thereof.
• the kumaron inden resin is a resin containing kumaron and inden as monomer components constituting the skeleton (main chain) of the resin.
• Examples of the monomer component contained in the skeleton other than kumaron and indene include styrene, ⁇ -methylstyrene, methylindene, vinyltoluene and the like.
• the content of the Kumaron indene resin is, for example, more than 1.0 part by mass and less than 50.0 parts by mass with respect to 100 parts by mass of the rubber component.
• the hydroxyl value (OH value) of the Kumaron indene resin is, for example, more than 15 mgKOH / g and less than 150 mgKOH / g.
• the OH value is the amount of potassium hydroxide required to neutralize the acetic acid bonded to the hydroxyl group when acetylating 1 g of the resin in milligrams, and is represented by the potential difference dropping method (JIS K 0070:). It is a value measured by 1992).
• the softening point of the Kumaron indene resin is, for example, more than 30 ° C and less than 160 ° C.
• the softening point is the temperature at which the ball drops when the softening point defined in JIS K 6220-1: 2001 is measured by a ring-ball type softening point measuring device.
• Terpene resin examples include polyterpenes, terpene phenols, aromatic-modified terpene resins and the like.
• Polyterpene is a resin obtained by polymerizing a terpene compound and a hydrogenated additive thereof.
• the terpene compound is a hydrocarbon having a composition of ( C 5 H 8 ) n and an oxygen - containing derivative thereof . ) Etc., which are compounds having a terpene as a basic skeleton. , 1,8-Cineol, 1,4-Cineol, ⁇ -terpineol, ⁇ -terpineol, ⁇ -terpineol and the like.
• polyterpene examples include terpene resins such as ⁇ -pinene resin, ⁇ -pinene resin, limonene resin, dipentene resin, and ⁇ -pinene / limonene resin made from the above-mentioned terpene compound, as well as hydrogen obtained by hydrogenating the terpene resin.
• Additive terpene resin can also be mentioned.
• the terpene phenol include a resin obtained by copolymerizing the above-mentioned terpene compound and the phenol-based compound, and a resin obtained by hydrogenating the resin. Specifically, the above-mentioned terpene compound, the phenol-based compound and the formalin are condensed. Resin is mentioned.
• Examples of the phenolic compound include phenol, bisphenol A, cresol, xylenol and the like.
• examples of the aromatic-modified terpene resin include a resin obtained by modifying a terpene resin with an aromatic compound, and a resin obtained by hydrogenating the resin.
• the aromatic compound is not particularly limited as long as it is a compound having an aromatic ring, and for example, a phenol compound such as a phenol, an alkylphenol, an alkoxyphenol, or an unsaturated hydrocarbon group-containing phenol; naphthol, alkylnaphthol, alkoxynaphthol, etc.
• Naftor compounds such as unsaturated hydrocarbon group-containing naphthols; styrene derivatives such as styrene, alkylstyrene, alkoxystyrene, unsaturated hydrocarbon group-containing styrene; kumaron, inden and the like can be mentioned.
• C5 resin refers to a resin obtained by polymerizing a C5 fraction.
• the C5 fraction include petroleum distillates having 4 to 5 carbon atoms such as cyclopentadiene, pentene, pentadiene, and isoprene.
• a dicyclopentadiene resin DCPD resin
• DCPD resin dicyclopentadiene resin
• the "C9 resin” refers to a resin obtained by polymerizing a C9 fraction, and may be hydrogenated or modified.
• the C9 fraction include petroleum fractions having 8 to 10 carbon atoms such as vinyltoluene, alkylstyrene, indene, and methyl indene.
• a kumaron indene resin, a kumaron resin, an indene resin, and an aromatic vinyl-based resin are preferably used.
• aromatic vinyl resin a homopolymer of ⁇ -methylstyrene or styrene or a copolymer of ⁇ -methylstyrene and styrene is preferable because it is economical, easy to process, and excellent in heat generation. , A polymer of ⁇ -methylstyrene and styrene is more preferred.
• aromatic vinyl-based resin for example, those commercially available from Clayton, Eastman Chemical, etc. can be used.
• C5C9 resin refers to a resin obtained by copolymerizing the C5 fraction and the C9 fraction, and may be hydrogenated or modified.
• Examples of the C5 fraction and the C9 fraction include the above-mentioned petroleum fraction.
• As the C5C9 resin for example, those commercially available from Tosoh Corporation, LUHUA, etc. can be used.
• the acrylic resin is not particularly limited, but for example, a solvent-free acrylic resin can be used.
• the solvent-free acrylic resin is a high-temperature continuous polymerization method (high-temperature continuous lump polymerization method) (US Pat. No. 4,414,370) without using a polymerization initiator, a chain transfer agent, an organic solvent, etc. as auxiliary raw materials as much as possible.
• Examples thereof include a (meth) acrylic resin (polymer) synthesized by the method described in ⁇ 45 and the like).
• (meth) acrylic means methacrylic and acrylic.
• Examples of the monomer component constituting the acrylic resin include (meth) acrylic acid, (meth) acrylic acid ester (alkyl ester, aryl ester, aralkyl ester, etc.), (meth) acrylamide, and (meth) acrylamide derivative.
• (Meta) acrylic acid derivatives such as.
• acrylic resin styrene, ⁇ -methylstyrene, vinyltoluene, vinylnaphthalene, divinylbenzene, trivinylbenzene, divinylnaphthalene, etc., together with (meth) acrylic acid and (meth) acrylic acid derivative, etc.
• Aromatic vinyl may be used as the monomer component constituting the acrylic resin.
• the acrylic resin may be a resin composed of only a (meth) acrylic component or a resin having a component other than the (meth) acrylic component as a component. Further, the acrylic resin may have a hydroxyl group, a carboxyl group, a silanol group, or the like.
• Examples of the polymer component of the resin component include Maruzen Petrochemical Co., Ltd., Sumitomo Bakelite Co., Ltd., Yasuhara Chemical Co., Ltd., Toso Co., Ltd., Rutgers Chemicals Co., Ltd., BASF Co., Ltd., Arizona Chemical Co., Ltd., and Nikko Chemical Co., Ltd. , Nippon Catalyst Co., Ltd., JX Energy Co., Ltd., Arakawa Chemical Industry Co., Ltd., Taoka Chemical Industry Co., Ltd., etc. can be used.
• the rubber composition preferably contains an anti-aging agent.
• the content of the anti-aging agent is, for example, more than 1 part by mass and less than 10 parts by mass with respect to 100 parts by mass of the rubber component.
• antiaging agent examples include naphthylamine-based antiaging agents such as phenyl- ⁇ -naphthylamine; diphenylamine-based antiaging agents such as octylated diphenylamine and 4,4'-bis ( ⁇ , ⁇ '-dimethylbenzyl) diphenylamine; N. -Isopropyl-N'-phenyl-p-phenylenediamine, N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine, N, N'-di-2-naphthyl-p-phenylenediamine, etc.
• P-Phenylenediamine-based anti-aging agent P-Phenylenediamine-based anti-aging agent
• quinoline-based anti-aging agent such as a polymer of 2,2,4-trimethyl-1,2-dihydroquinolin
• 2,6-di-t-butyl-4-methylphenol Monophenolic antioxidants such as styrenated phenol; tetrakis- [methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] bis, tris
• polyphenolic aging such as methane Examples include inhibitors. These may be used alone or in combination of two or more.
• anti-aging agent for example, products of Seiko Chemical Co., Ltd., Sumitomo Chemical Co., Ltd., Ouchi Shinko Chemical Industry Co., Ltd., Flexis Co., Ltd., etc. can be used.
• the rubber composition may contain stearic acid.
• the content of stearic acid is, for example, more than 0.5 parts by mass and less than 10.0 parts by mass with respect to 100 parts by mass of the rubber component.
• stearic acid conventionally known ones can be used, and for example, products such as NOF Corporation, NOF Corporation, Kao Corporation, Wako Pure Chemical Industries, Ltd., and Chiba Fatty Acid Co., Ltd. can be used.
• the rubber composition may contain zinc oxide.
• the content of zinc oxide is, for example, more than 0.5 parts by mass and less than 10 parts by mass with respect to 100 parts by mass of the rubber component.
• Conventionally known zinc oxide can be used.
• products of Mitsui Metal Mining Co., Ltd., Toho Zinc Co., Ltd., HakusuiTech Co., Ltd., Shodo Chemical Industry Co., Ltd., Sakai Chemical Industry Co., Ltd., etc. Can be used.
• Each rubber composition preferably contains wax.
• the content of the wax is, for example, 0.5 to 20 parts by mass, preferably 1.5 to 15 parts by mass, and more preferably 3.0 to 10.0 parts by mass with respect to 100 parts by mass of the rubber component.
• the wax is not particularly limited, and examples thereof include petroleum wax such as paraffin wax and microcrystalline wax; natural wax such as plant wax and animal wax; and synthetic wax such as a polymer such as ethylene and propylene. These may be used alone or in combination of two or more.
• wax for example, products such as Ouchi Shinko Kagaku Kogyo Co., Ltd., Nippon Seiro Co., Ltd., and Seiko Kagaku Co., Ltd. can be used.
• the rubber composition preferably contains a cross-linking agent such as sulfur.
• the content of the cross-linking agent is, for example, more than 0.1 part by mass and less than 10.0 parts by mass with respect to 100 parts by mass of the rubber component.
• sulfur examples include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersible sulfur, and soluble sulfur, which are generally used in the rubber industry. These may be used alone or in combination of two or more.
• sulfur for example, products such as Tsurumi Chemical Industry Co., Ltd., Karuizawa Sulfur Co., Ltd., Shikoku Chemicals Corporation, Flexis Co., Ltd., Nippon Inui Kogyo Co., Ltd., Hosoi Chemical Industry Co., Ltd. can be used. ..
• cross-linking agent other than sulfur examples include Tackilol V200 manufactured by Taoka Chemical Industry Co., Ltd., DURALINK HTS (1,6-hexamethylene-sodium dithiosulfate / dihydrate) manufactured by Flexis, and KA9188 manufactured by LANXESS.
• examples thereof include a vulcanizing agent containing a sulfur atom such as (1,6-bis (N, N'-dibenzylthiocarbamoyldithio) hexane) and an organic peroxide such as dicumyl peroxide.
• the rubber composition preferably contains a vulcanization accelerator.
• the content of the vulcanization accelerator is, for example, more than 0.3 parts by mass and less than 10.0 parts by mass with respect to 100 parts by mass of the rubber component.
• sulfide accelerator examples include thiazole-based sulfide accelerators such as 2-mercaptobenzothiazole, di-2-benzothiazolyl disulfide, and N-cyclohexyl-2-benzothiadylsulfenamide; tetramethylthiuram disulfide (TMTD).
• thiazole-based sulfide accelerators such as 2-mercaptobenzothiazole, di-2-benzothiazolyl disulfide, and N-cyclohexyl-2-benzothiadylsulfenamide
• TMTD tetramethylthiuram disulfide
• TzTD Tetrabenzyl thiuram disulfide
• TOT-N tetrakis (2-ethylhexyl) thiuram disulfide
• other thiuram-based sulfide accelerators N-cyclohexyl-2-benzothiazolesulfenamide, N-t-butyl- 2-benzothiazolyl sulfenamide, N-oxyethylene-2-benzothiazolesulfenamide, N-oxyethylene-2-benzothiazolesulfenamide, N, N'-diisopropyl-2-benzothiazolesulfenamide, etc.
• Sulfenamide-based sulphurization accelerator such as diphenylguanidine, dioltotrilguanidine, orthotrilbiguanidine can be mentioned. These may be used alone or in combination of two or more.
• the rubber composition is further blended with additives generally used in the tire industry, such as fatty acid metal salts, carboxylic acid metal salts, organic peroxides, and graphite. May be.
• additives generally used in the tire industry such as fatty acid metal salts, carboxylic acid metal salts, organic peroxides, and graphite. May be.
• the content of these additives is, for example, more than 0.1 part by mass and less than 200 parts by mass with respect to 100 parts by mass of the rubber component.
• the rubber composition is prepared by a general method, for example, a base kneading step of kneading a rubber component with a filler such as silica or carbon black, and a kneaded product and a cross-linking agent obtained in the base kneading step. It is produced by a manufacturing method including a finishing kneading step of kneading and kneading.
• Kneading can be performed using a known (sealed) kneader such as a Banbury mixer, a kneader, or an open roll.
• a known (sealed) kneader such as a Banbury mixer, a kneader, or an open roll.
• the kneading temperature of the base kneading step is, for example, more than 50 ° C. and less than 200 ° C.
• the kneading time is, for example, more than 30 seconds and less than 30 minutes.
• compounding agents conventionally used in the rubber industry such as softeners such as oil, stearic acid, zinc oxide, antiaging agents, waxes, vulcanization accelerators, etc., are used as needed. May be added and kneaded as appropriate.
• the finish kneading step the kneaded product obtained in the base kneading step and the cross-linking agent are kneaded.
• the kneading temperature of the finish kneading step is, for example, above room temperature and less than 80 ° C.
• the kneading time is, for example, more than 1 minute and less than 15 minutes.
• a vulcanization accelerator, zinc oxide and the like may be appropriately added and kneaded as needed.
• the thermal conductivity of the rubber composition can be adjusted by adjusting the blending ratio of carbon black, silica, etc., or by blending graphene, graphite, carbon nanofibers, etc. can.
• the tire of the present invention is manufactured by a usual method using an unvulcanized rubber composition obtained through the finishing kneading step. Specifically, first, the unvulcanized rubber composition is extruded according to the shape of each tire member of the tread. At this time, by simultaneously extruding the rubber compositions having different thermal conductivity, it is possible to obtain a tread having a region having different thermal conductivity.
• an unvulcanized tire is manufactured by molding on a tire molding machine by a normal method together with other tire members. Specifically, on the molded drum, the inner liner as a member to ensure the airtightness of the tire, the carcass as a member to withstand the load, impact, and filling air pressure received by the tire, and the carcass as a member to withstand the filling air pressure are strongly tightened to increase the rigidity of the tread.
• a belt or the like as a member to be raised is wound, both ends of the carcass are fixed to both side edges, and a bead part as a member for fixing the tire to the rim is arranged and formed into a toroid shape, and then the center of the outer circumference.
• An unvulcanized tire is manufactured by laminating a tread on the portion and a sidewall portion as a member that protects the carcass on the outside in the radial direction and withstands bending.
• the belt is provided with an inclined belt layer that extends at an angle of 15 ° to 30 ° with respect to the tire circumferential direction, thereby ensuring the durability of the tire.
• the rigidity of the tread can be sufficiently maintained. Further, since it can be restrained in the circumferential direction, it becomes easy to suppress the growth of the outer diameter.
• the vulcanization step can be carried out by applying a known vulcanization means.
• the vulcanization temperature is, for example, more than 120 ° C. and less than 200 ° C.
• the vulcanization time is, for example, more than 5 minutes and less than 15 minutes.
• the tire is incorporated into a regular rim, and when the internal pressure is 250 kPa, the tire is molded into a shape that satisfies the above (formula 1) and (formula 2).
• Specific tires that can satisfy the above (formula 1) and (formula 2) include 145 / 60R18, 145 / 60R19, 155 / 55R18, 155 / 55R19, 155 / 70R17, 155 / 70R19, 165 / 55R20. , 165 / 55R21, 165 / 60R19, 165 / 65R19, 165 / 70R18, 175 / 55R19, 175 / 55R20, 175 / 55R22, 175 / 60R18, 185 / 55R19, 185 / 60R20, 195 / 50R20, 195 / 55R20, etc. Examples are tires with size notation.
• the pneumatic tire for a passenger car referred to here is a tire mounted on a vehicle traveling on four wheels and has a maximum load capacity of 1000 kg or less.
• the maximum load capacity is the maximum load capacity defined for each tire in the standard system including the standard on which the tire is based. For example, if it is the JATTA standard (Japan Automobile Tire Association standard), it is loaded. Maximum load capacity based on index (LI), maximum value described in "TIRE LOAD LIMITS AT VARIOUS COLD INFRATION PRESSURES" for TRA (The Tire and Rim Association, Inc.), "INFRATION” for ETRTO ..
• the maximum load capacity is not particularly limited as long as it is 1000 kg or less, but in general, the tire weight tends to increase as the maximum load capacity increases, and the braking distance also increases due to inertia accordingly. Therefore, the maximum load capacity is 900 kg or less. It is preferably 800 kg or less, more preferably 700 kg or less.
• the tire weight is preferably 20 kg or less, more preferably 15 kg or less, and further preferably 12 kg or less, 10 kg or less, and 8 kg or less from the viewpoint of the braking distance due to the inertia described above.
• the tire of the present invention may be provided with electronic components, and in this case, the tire weight referred to here is the tire weight including the weights of the electronic components and the electronic component mounting members. If a sealant, sponge, or the like is provided in the lumen, the weight of the tire includes them.
• Blending material First, each blending material shown below was prepared.
• Rubber component (a) NR: TSR20 (B) BR: UBEPOL BR150 manufactured by Ube Industries, Ltd. (Sis content: 97% by mass, trans amount: 2% by mass, vinyl bond amount: 1% by mass) (C) SBR: Europrene SOL RC2525 manufactured by Versalis (Styrene content: 26% by mass, vinyl bond amount: 24% by mass)
• (B) Blending materials other than rubber components (a) Carbon black-1: Seast F manufactured by Tokai Carbon Co., Ltd. (B) Carbon Black-2: Gepan Black EC300J manufactured by Gepan Black International Co., Ltd. (C) Silica: Ultrasil VN3 manufactured by Evonik Industries (D) Silane coupling agent: Si363 manufactured by Degussa (E) Oil: Process oil A / OMIX manufactured by Sankyo Yuka Kogyo Co., Ltd. (F) Wax: Ozoace 0355 manufactured by Nippon Seiro Co., Ltd. (G) Stearic acid: Stearic acid "Camellia” manufactured by NOF CORPORATION (H) Zinc oxide: Zinc oxide No.
• NR is 50 parts by mass
• BR is 40 parts by mass
• SBR is 10 parts by mass.
• Stealic acid is 2 parts by mass
• zinc oxide is 3 parts by mass
• anti-aging agent is 3 parts by mass
• sulfur is 1.5 parts by mass
• vulture accelerator-1 is 1 part by mass
• vulture accelerator-2 is 0.
• a rubber composition (Kb: 0.30 W / m ⁇ K) having a low thermal conductivity was obtained by performing base kneading and finish kneading with a compounding of 5.5 parts by mass.
• the loss tangent (30 ° C. tan ⁇ ) of this rubber composition was measured using the Iplexer series manufactured by GABO under the conditions of 30 ° C., frequency 10 Hz, initial strain 5%, and dynamic strain rate 1%. , 0.14.
• the above-mentioned (L 80 / L 0 ) is 0.5
• the total cross-sectional area of the circumferential groove is 22% of the cross-sectional area of the tread portion
• the groove width / groove depth is 0.
• the total volume of the lateral grooves including the lateral grooves of 65 was set to 3.5% of the volume of the tread portion.
• each test tire is attached to all wheels of the vehicle (domestic FF vehicle, displacement 2000cc), filled with air so that the internal pressure becomes 250 kPa, and then on the test course on a dry road surface.
• the vehicle domestic FF vehicle, displacement 2000cc
• the distance from when the accelerator was released and the accelerator was turned off until the vehicle stopped was measured as rolling resistance at high speed. The larger the value, the longer the distance from the timing when the accelerator is turned off until the vehicle stops, and the smaller the rolling resistance in the steady state.
• Example 4-3 was set as 100, and the index was indexed based on the following formula to evaluate the fuel efficiency.

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• 2020
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