{
  "$type": "site.standard.document",
  "description": "Provided is a pneumatic tire having a sufficiently suppressed change in handling property and sufficiently improved durability. This pneumatic tire comprises a tread portion including a rubber layer, the rubber layer is formed of a rubber composition having 0.25 or less of a loss tangent (15°C…",
  "path": "/patents/1399932",
  "publishedAt": "2025-10-08T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "B60C1/00",
    "SUMITOMO RUBBER IND [JP]"
  ],
  "textContent": "Provided is a pneumatic tire having a sufficiently suppressed change in handling property and sufficiently improved durability. This pneumatic tire comprises a tread portion including a rubber layer, the rubber layer is formed of a rubber composition having 0.25 or less of a loss tangent (15°C tanδ) measured under such conditions as 15°C, frequency 10 Hz, initial strain 5%, and dynamic strain rate 1%, the tread portion includes a plurality of rib-like land portions formed by circumferential grooves continuously extending in the circumferential direction, the tread portion has a ground contact surface partitioned, at the equatorial plane, such that one ground contact area Sa and the other ground contact area Sb satisfy a relationship of Sa>Sb, and (formula 1) and (formula 2) are satisfied where Wt (mm) is the cross sectional width of the tire, Dt (mm) is the outer diameter, and V (mm3) is a virtual volume being the volume of a space occupied by the tire when the tire is mounted on a standard rim and the internal pressure is 250 kPa. 1600≤Dt2×π/4/Wt≤2827.4V+1.5×107/Wt≤2.88×105",
  "title": "PNEUMATIC TIRE"
}