{
  "$type": "site.standard.document",
  "description": "Provided is a pneumatic radial tire for a passenger car that exhibits both riding comfort at low temperatures and stealing stability at high-speed running. The present invention is a pneumatic radial tire for a passenger car, in which: a carcass and a tread are provided; the tread is integrated…",
  "path": "/patents/1401672",
  "publishedAt": "2025-12-24T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "B60C1/0016",
    "SUMITOMO RUBBER IND [JP]"
  ],
  "textContent": "Provided is a pneumatic radial tire for a passenger car that exhibits both riding comfort at low temperatures and stealing stability at high-speed running. The present invention is a pneumatic radial tire for a passenger car, in which: a carcass and a tread are provided; the tread is integrated into a standardized rim; when internal pressure is at a standardized internal pressure, the tire has a cross-sectional width Wt (mm) and an outer diameter Dt (mm) satisfying 1963.4 ≤ (Dt × π/4)/Wt ≤ 2827.4; the tread comprises at least one main groove in a running surface of the tread, extending in the circumferential direction of the tread; the land/sea ratio at the tread running surface is greater than 55% and less than 85%; and a rubber composition that forms the tread has a loss tangent (tanδ) which, when measured at a frequency of 10 Hz, an initial strain of 2%, and a dynamic strain rate of 1%, is such that |20°C tanδ-50°C tanδ| is at least 0.01 and less than 0.15, and |5°C tanδ-20°C tanδ| is greater than 0.15 and less than 0.70.",
  "title": "PNEUMATIC RADIAL TIRE FOR PASSENGER VEHICLE"
}