Sumitomo Rubber Industries Limited

Subaru Toya

Takahiro Kawachi

Masako Nakatani

Hiroki Kawai

Ayuko Yamada

Kenji Hamamura

Hiroshi Ito

Takuya Horiguchi

Tatsuhiro Tanaka

Shuichiro Ono

Takayuki Nagase

Keiji Takagi

Hayato Yoshiyasu

Fumiya Kato

Tetsuya Maekawa

Keiichi Nakadera

Takehiro Kitaura

Nanaho Kami

Masataka Hiro

Hiroaki Yamada

Daiki Mukouguchi

A pneumatic tire having a tread, wherein the ground contact surface of the tread is composed of at least two types of rubber compositions different in the thermal conductivity, and the following formulas (1) and (2) are satisfied:1700≤(×π/4)/≤2827.4  (1)[(+1.5×10)/]≤2.88×10  (2)where Wt (mm) is the cross-sectional width and Dt (mm) is the outer diameter of the tire when installed on a standardized rim and inflated to an internal pressure of 250 kPa, and V (mm) is the virtual volume of the space occupied by the tire.

Pneumatic tire

Provided is a pneumatic tire that has reduced rolling resistance during high-speed running as well as excellent durability performance. This pneumatic tire comprises a sidewall and a clinch section in each of a pair of side sections. When the loss tangent of the sidewall is tan δsw and the loss tangent of the clinch section is tan δc when measured under the conditions of 70° C., a frequency of 10 Hz, an initial strain of 5%, and a dynamic strain rate of 1%, then (tan δsw+tan δc)≤0.3 and |tan δsw−tan δc|≤0.07. When the cross-sectional width of the tire is Wt (mm) and the external diameter is Dt (mm) when the pneumatic tire is installed on a standardized rim and internal pressure is set to 250 kPa, and if the volume of space occupied by the tire is a virtual volume V (mm), then (formula 1) and (formula 2) are satisfied.1700≤(×π/4)/≤2827.4  (formula 1)[(+1.5×10)/]≤2.88×10  (formula 2).

Provided is a pneumatic tire for which rolling resistance at high speed running is sufficiently reduced and durability is sufficiently improved. The pneumatic tire has a side portion, a thickness S (mm) of a rubber layer radially outside a carcass on the side portion at the maximum tire width position is 3 mm or less, the loss tangent of the rubber layer measured under the conditions of 70° C., a frequency of 10 Hz, an initial distortion of 5%, and a dynamic distortion rate of 1% is 0.15 or less, and when the cross-sectional width of the tire is Wt (mm) and the outer diameter is Dt (mm) when installed on a regular rim and the internal pressure is 250 kPa, the volume of the space occupied by the tire is the virtual volume V (mm), the following (formula 1) and (formula 2) are satisfied.1700≤(×π/4)/≤2827.4  (formula 1)[(+1.5×10)/]≤2.88×10  (formula 2)

A pneumatic tireincludes a carcassextending between bead cores of bead portions via a tread portionand sidewall portions, and a belt layerarranged on an outer side in a tire radial direction of the carcassand inside the tread portion. The pneumatic tirehas a noise damperarranged on an inner cavity surface of the tread portion. Glass transition temperature of the noise damperis in a range of from −55 degrees Celsius to −45 degrees Celsius.

The present invention provides a rubber composition for tires which provides improved abrasion resistance, and a pneumatic tire containing the rubber composition. The present invention relates to a rubber composition for tires containing a rubber component including at least 80% by mass in total of at least one of an isoprene-based rubber, a polybutadiene rubber, or a styrene-butadiene rubber, the rubber composition containing, per 100 parts by mass of the rubber component, 3 to 250 parts by mass of a reinforcing filler and 0.2 to 10 parts by mass of a specific tetrazine compound.

Rubber composition for tires and pneumatic tire

A pneumatic tirecomprises a carcassextending between bead cores of bead portions via a tread portionand sidewall portions, and a belt layerarranged on an outer side in a tire radial direction of the carcassand inside of the tread portion. The pneumatic tirefurther comprises a damping rubber bodyarranged between the carcassand the belt layer, and a noise damperarranged on an inner cavity surface of the tread portion. A width Win a tire axial direction of the damping rubber bodyis in a range of from 60% to 130% of a width Win the tire axial direction of the belt layer, and a water absorption rate of the noise damperis in a range of from 10% to 25%.

The present invention provides a pneumatic tire and a rubber composition for tires, which have improved durability at high temperatures and during high-speed running while ensuring good ice performance. The present invention relates to a pneumatic tire, including a tread, the tread including blocks having an average ripe density of 1.0 cm/cmor higher and an average height of 0.6 to 2.0 cm, the blocks containing a rubber composition having a tan &#x3b4; at 100&#xb0; C. of 0.179 or less as determined at an initial strain of 10%, a dynamic strain of 2%, and a frequency of 10 Hz, and has a ratio of the modulus at 100&#xb0; C. to the modulus at room temperature of 69% or greater as determined in accordance with JIS K6251:2010.

Pneumatic tire, and rubber composition for tire

To be capable of preventing deterioration of uniformity after puncture repair while suppressing running noise. [Solution] A pneumatic tirecomprises a noise damperfixed to a tire inner cavity surface of a tread portionand formed of a porous material. The noise damperincludes a first partarranged on an outer side in a tire radial direction and fixed to the tire inner cavity surface, and a second partarranged on an inner side in the tire radial direction of the first partand exposed in a tire inner cavity. A water absorption rate of the first partcalculated by a following formula (1) is in a range of from 5% to 25%. Air permeability of the second partmeasured in accordance with Japanese Industrial Standard JIS-L1096 is in a range of from 1 to 7 cm3/cm2/s. The formula (1) is:water absorption rate (%)=weight change before and after immersion (g)/volume at 50% compression (cm3)&#xd7;100 &#x2003;&#x2003;(1).

Growing community of inventors

Kobe, Japan

Subaru Toya