Pneumatic tire
View Patent ↗A pneumatic tire includes an inner liner layer formed from a laminate sheet obtained by laminating: a sheet made from a thermoplastic resin or a thermoplastic resin composition which is a blend of the thermoplastic resin and an elastomer; and a rubber bonded by curing to the thermoplastic resin or the thermoplastic resin composition. The pneumatic tire avoids occurrence of cracks near a splice portion of the inner liner layer after the pneumatic tire starts to be used for driving, and thereby achieves excellent durability. In the tire, an inner liner layer is formed by lap-splicing end portions of a laminate sheet which is obtained by the laminating A sheet with end portions each having a tip subjected to a tip sharpening process is used as the sheet made from the thermoplastic resin or the thermoplastic resin composition which is the blend of the thermoplastic resin and the elastomer.
1. A pneumatic tire including
an inner liner layer which is lap-spliced and has a sheet made from a thermoplastic resin or a thermoplastic resin composition which is a blend of the thermoplastic resin and an elastomer, and a rubber, and the sheet including end portions, each of the end portions having a sharpened tip,
each of the sharpened tips of the sheet having a thickness T (μm) that has a relationship which satisfies 0.1t≤T≤0.8t, where
t represents an average thickness (μm), in a tire radial direction, of a tip-sharpening-unprocessed part of the sheet, and
T represents the thickness (μm) of the sheet in a location inward in a tire circumferential direction by a length (t×⅓) from an end of each of the sharpened tips of the sheet,
the inner liner layer having an overlapping portion in which the end portions of the sheet overlap each other throughout an entirety of the overlapping portion in the tire radial direction, the overlapping portion including a first surface and a second surface that oppositely face relative to each other, the first surface of the overlapping portion being formed by both the sheet and the rubber with the rubber overlapping one of the sharpened tips, one of the end portions, which forms the first surface of the overlapping portion, having the one of the sharpened tips, the second surface of the overlapping portion being formed solely by the rubber.
2. The pneumatic tire of claim 1 , wherein
each of the sharpened tips of the sheet extends in a length L to a location inward from the end of each of the sharpened tips, with the length L being expressed by L=(1.0 to 20)×t (μm).
3. The pneumatic tire of claim 1 , wherein
each of the sharpened tips of the sheet extends in a length L to a location inward from the end of each of the sharpened tips, with the length L being expressed by L=(1.0 to 2.5)×t (μm).
4. The pneumatic tire of claim 1 , wherein
the sheet is made from the thermoplastic resin composition which is the blend of the thermoplastic resin and the elastomer, and
on a surface of each of the sharpened tips, the elastomer is covered with a film of the thermoplastic resin.
5. The pneumatic tire of claim 2 , wherein
the sheet is made from the thermoplastic resin composition which is the blend of the thermoplastic resin and the elastomer, and
on a surface of each of the sharpened tips, the elastomer is covered with a film of the thermoplastic resin.
6. The pneumatic tire of claim 3 , wherein
the sheet is made from the thermoplastic resin composition which is the blend of the thermoplastic resin and the elastomer, and
on a surface of each of the sharpened tips, the elastomer is covered with a film of the thermoplastic resin.